The Roman Mysteries

The Roman Mysteries is a series of historical detective novels for children, written by Caroline Lawrence. It is set in The Roman Empire during the 1st century AD. The books follow four children who solve mysteries and have adventures in Ostia, Rome, and throughout the empire. The lead character, Flavia, a middle-class Roman girl who lives in Ostia, is a self-styled detectrix. She is supported by Nubia, a slave girl from Africa; Jonathan, a Jewish boy; and Lupus, a mute beggar boy. CBBC adapted some of the books into a Live Action TV show.

Caroline Lawrence has started a sequal series called The Roman Mystery Scrolls, written for a slightly younger audience. She is also the author of The Western Mysteries.

The main novels of the Roman Mysteries series are:

The Thieves of Ostia (2001)
The Secrets of Vesuvius (2001)
The Pirates of Pompeii (2002)
The Assassins of Rome (2002)
The Dolphins of Laurentum (2003)
The Twelve Tasks of Flavia Gemina (2003)
The Enemies of Jupiter (2003)
The Gladiators from Capua (2004)
The Colossus of Rhodes (2005)
The Fugitive from Corinth (2005)
The Sirens of Surrentum (2006)
The Charioteer of Delphi (2006)
The Slave-girl from Jerusalem (2007)
The Beggar of Volubilis (2008)
The Scribes from Alexandria (2008)
The Prophet from Ephesus (2009)
The Man from Pomegranate Street (2009)

Additional books include:

The Code of Romulus (2007): A novella published for World Book Day.
Trimalchio's Feast and other mini-mysteries (2007): A collection of short stories.
- "The Case of the Missing Coin": Takes place after The Thieves of Ostia
- "Trimalchio's Feast": Takes place after The Twelve Tasks of Flavia Gemina
- "Jonathan Vs. Ira": Takes place after The Enemies of Jupiter
- "The Case of the Citrus-Wood Table": Takes place after The Gladiators from Capua
- "The Case of the Talking Statue": Takes place after The Charioteer of Delphi
- "Death By Vespian": Takes place after The Slave-girl from Jerusalem
The Roman Mysteries Treasury (2007): A companion book with additional background information about the characters and factual information about The Roman Empire.
Frome Ostia to Alexandria with Flavia Gemini (2008): A travel guide to the places mentioned in the series, based on Caroline Lawrence's own experience doing research trips for her stories.
The Legionary from Londinium and other mini-mysteries (2010): A collection of short stories.
- "The Moon in Full Daylight": Takes place after The Sirens of Surrentum
- "The Legionary from Londinium": Takes place after The Sirens of Surrentum
- "Death by Medusa": Takes place before The Charioteer of Delphi
- "The Perseus Prophecy": Takes place after The Charioteer of Delphi
- "The Five Barley Grains": Takes place before The Slave-girl from Jerusalem
- "Threptus and the Sacred Chickens": Takes place after The Man from Pomegranate Street

The following tropes are common to many or all entries in the The Roman Mysteries franchise.
For tropes specific to individual installments, visit their respective work pages.

Tropes A though D

Age-Appropriate Angst: There are several examples of this throughout the series, including Flavia's reaction to a Parent with New Paramour in The Twelve Tasks of Flavia Gemina.
All There in the Manual: The Roman Mysteries Treasury contains additional information about the characters, their backgrounds and the setting (namely The Roman Empire),
Amateur Sleuth: Flavia and friends
Androcles' Lion: Played with. A tame lion that is friendly with a character that has been sentenced to be eaten by lions is substituted for the wild man-eating lion.
Appease the Volcano God: The books actually give a real life twist on this common trope. Instead of virgin sacrifice, the Romans sacrifice fish as part of the Vulcanalia in The Secrets of Vesuvius.
Arranged Marriage: Common practice during the time period in which the books are set, the marriage of Jonathan's parent's is explicitly stated to have been arranged, and many of the other marriages depicted were probably also arranged. This custom causes conflict between Flavia and her father when her father wants to arrange a betrothal for her.
Artful Dodger: Lupus's life as a beggar boy and innate intelligence makes him sneaky and street smart.
Bear Trap: Poor Lupus gets stuck in a boar trap. Fortunately it is not bad as a Bear Trap, but is was still pretty bad.
Big Bad: Some of the books have villains and others do not, however the villain whose kidnapping ring forms one of the recurring plot lines of the series is referred to by the characters is "The Big Buyer". After the "Big Buyer" is captured, it is revealed that there is a "Bigger Buyer" who is in fact ultimately in charge of the slave ring.
Big Fancy House: Detailed descriptions of the housing of various characters, to include maps of the houses, are used both to indicate wealth and to educate about historic Roman housing. Villa Limona is a good example of a truly big and fancy house.
The Big Guy: Caudex is a large, strong slave that often acts as a a body guard for the main characters.
Bilingual Bonus: Many of the books contain some Latin words; however most are translated either in the main text or in the glossary. In one story, however, one of the clues requires an understanding of Latin. A character says a word that is written in English, however if the word is translated back into the Latin that he would have actually been speaking, it points to the identity of the killer.
Bittersweet Ending: The Slave-girl from Jerusalem and The Man from Pomegranate Street.
- Specifically, the four detectives are exiled from their homeland and Jonathan's nephew is still missing three years later. This may be cleared up in future spin-offs.
Bonding Over Missing Parents: There is a scene where the four children discuss their Missing Moms and are reduced to tears.
Bonus Material: A glossary and a note from the author about the actual history behind the story is added to the end of each book. Some of the books also include maps and diagrams.
Black Vikings: Averted in the books, which contain a realistic depictions of the racial and cultural mix of the Roman Empire. However, in the TV adaptation, there are two examples of black Roman patricians.
Bookworm: Flavia is a big fan of reading. In the first book, she wanted a copy of Pliny's Natural History as her birthday present.
Breaking the Fellowship: This happens in The Scribes from Alexandria, when the main characters are split up by a shipwreck.
Casanova: Publius Pollus Felix, as revealed in The Sirens of Surrentum, not only has sex with pretty much all his slavegirls (normal for Romans), but also with many of the free-born girls in the neighborhood, which was considered much less acceptable and is depicted as being predatory in nature.
Chariot Race: Chariot races forms the center of the plot in The Charioteer of Delphi.
The Chase: The Colossus of Rhodes, The Fugitive from Corinth, The Scribes from Alexandria, and The Prophet from Ephesus.
Chekhov's Volcano: The Secrets of Vesuvius has the characters going to the area near Pompeii, just in time for the now famous eruption of Mount Vesuvius.
Classical Mythology: All the books have both explicit references to Classical Myths and intentional parallels to the referenced myths within the story line.
Cleaning Up Romantic Loose Ends: Part of the plot of The Man from Pomegranate Street, though not a complete example because several of the major characters end up without partners in the end.
Clear Their Name: The Slave-girl from Jerusalem involves clearing the name of a slave-girl falsely accused or murder.
Cool Teacher: Aristo
Crossing the Desert: The Beggar of Volubilis
Cruel and Unusual Death: The Romans were big fans of this. Several historically accurate examples of particularly brutal and horrific executions appear The Gladiators from Capua. Some of the examples include criminals being Fed to the Beast and Eaten Alive. Sometimes this involves being Chained to a Rock.
Dark and Troubled Past: Both Lupus and Nubia suffered traumatic events in their past that continue to haunt them throughout the series.
Deathbringer the Adorable: The rabbit in The Gladiators from Capua has a name that indicates it is a ferocious beast, but it is really just a harmless bunny.
Death by Childbirth: Flavia's mother, in Flavia's Backstory, and Miriam at the end of 'The Slave-girl from Jerusalem both die giving birth to twins.
Deliberately Cute Child: Sometimes Flavia uses this trick during the course of an investigation.
Deliberate Values Dissonance: All the characters freak out over free Romans being kidnapped and enslaved, but most of them give little thought to the enslavement of non-Romans or those born to slavery. Notable exceptions are Nubia, who was herself a slave, and Dr. Mordecai, who is against all slavery. This is not an example of dissonance on the part of the author, but an accurate potrayal of the values of the time period. Likewise, it accurately presents Roman marriage customs and Roman views on Blood Sports and execution as entertainment.
Distant Finale: The final chapter of the last book skips several years from the end of the previous chapter.
Drowning My Sorrows: Several adult character do this.

Tropes E though H

Ending Memorial Service: The funeral for Miriam at the end of The Slave-girl of Jerusalem.
Enthusiasm Versus Stoicism: The Sirens of Surrentum explores the differences between the Classical Greco-Roman philosophies of Epicureanism and Stoicism, with examples of characters that actively persue each of the two philosophies. The contrast might also be compared to Emotions vs. Stoicism.
Exactly What It Says on the Tin: Both the series title and many of the individual story titles
The Exotic Detective: Flavia is exotic in that she is a Kid Detective and an ancient Roman.
Everything's Better with Monkeys: In Trimalchio's Feast the titular monkey doesn't necessarily make things better, but he certainly makes things more chaotic and amusing.
Fair Play Whodunnit: Most of the stories
Faking The Dead: Historical Domain Character Gaius Valerius Flaccus fakes his death in order to go into exile with Flavia an marry her, as part of the Happily Ever After ending. This is used by the author to overcome the fact that the Real Life Flaccus died shortly after the stories end.
- Death Faked for You: This is done inadvertently. A boy that had stolen Jonathan's ring is killed in a fire. Finding his body makes everyone think that Jonathan is dead, which is fine with Jonathan because he wants to leave his identity behind and become a gladiator.
Famous Last Words: Real Life Emperor Nero's Real Life Famous Last Words are referenced in The Beggar of Volubilis, though it is suggested that they may have actually been something less grandiose. Emperor Vespian's Real Life Famous Last Words are also quoted in The Thieves of Ostia'.'
Feminine Women Can Cook: Alma and Miriam are the best cooks and play the most traditionally feminine roles in the story, especially by 1st Century Roman standards. Flavia, on the other hand, is hardly ever depicted cooking, partly because she is a Tomboy and partly because Alma does all the cooking for her family.
First Kiss: Flavia's first kiss is depicted in The Sirens of Surrentum.
Foreign Queasine: Stuffed dormice and other exotic period food.
Four-Temperament Ensemble: This is actually explicitly stated in the books, which is justified because it takes place during a time period when doctors still believed in the four humors.
Free-Range Children: The characters are often in situations where there is little adult supervision, especially toward the end of the series. However, this is not constant throughout the series, as there there are many situations where they do their detective work with adult supervision and help.
Friend to All Living Things: Nubia interacts well with animals and seems to has an empathy with them that sometimes borders on the supernatural.
Gentle Giant: Caudex, Monobaz
Giant Wall of Watery Doom: This happens off screen as the result of the eruption of Mount Vesuvius, which results in Marcus Flavius Geminus being shipwrecked and loosing his ship and all the money he had invested in his cargo, causing him to almost go bankrupt.
Gladiator Games: Gladiator games form the central theme of The Gladiators from Capua. Jonathan becomes a gladiator. Also a form of Blood Sport.
Hair-Trigger Temper: Lupus looses his temper easily, especially when people ask him about his past or mention his missing tongue.
Happily Ever After: The end of the final book, where Flavia get married. There is also an example of Wealthy Ever After, as the main characters have been given a luxurious villa and lots of money.
Happiness in Slavery: Played with. The series shows both the brutal and the relatively benign sides of Roman slavery, however even slaves that treated kindly and like their masters wish to be set free.
Harmful to Minors: Children are exposed to harmful situations and are even harmed throughout the series. Listed are just a few of the more notable examples.
- In The Gladiators from Capua, children, to include very young children are part of the audience at the ~~Colosseum~~ Flavian Amphitheater. Also, one of the main characters becomes a gladiator and another character is exposed to wild animals that kill several other children before she is saved.
- The events behind Lupus's Dark and Troubled Past and Nubia's Dark and Troubled Past.
- The fate of the children that are kidnapped and enslaved.
Heroic Dolphin meets Friendly Playful Dolphin: In The Roman Mysteries book The Dolphins of Laurentum. The main characters swim and play with dolpins, and Lupus even rides one. A dolphin rescues Lupus after he nearly drowns from staying underwater too long while diving. It is also strongly implied that the same dolphin discouraged Lupus from deliberatly leaving behind another diver who had been trapped by a giant octopus, though in fairness to Lupus he had a good reason for wanting the trapped person to die. The book also references several examples of the use of dolphins in Classical Mythology and Roman urban legends, including stories of shipwrecked sailors being rescued by dolphins and boys riding on dolphins. A ship is named Delphina.
Historical Fiction
The Hero: Flavia is the main Hero Protaganist of the stories, though all her friends have their moments in the spotlight and perform acts of heroism.
Heroic Self-Deprecation: Jonathan has a tendency towards pessimism and poor self esteem.
Heroic BSOD - Jonathan experiences this at the end of The Enemies of Jupiter when he blames himself for a massive fire that killed thousands of people. It results in examples of Hurting Hero, It's All My Fault, and Survivor Guilt. For a time, he also adopts an alter ego called Ira (meaning wrath) that almost results in Becoming the Mask. When his friends first try to shake him out of it, he expresses a That Man Is Dead attitude toward his real name and identity. His new identity includes some of the elements of Madden Into Misanthropy, A Darker Me, and something that may even be mild form of Split Personality.
Hurting Hero: Lupus is the main example at the beginning of the series. Jonathan also becomes one.

Tropes I though M

I Call It Vera: The door-slave (and former gladiator) Caudex has a sword he calls "Flora"; named, we are told, after an ex-girlfriend with a sharp tongue.
I Choose to Stay: Nubia does this at end at the end of The Scribes of Alexandria, when she chooses to return to Italia rather than go back to her home country of Nubia.
Idiosyncratic Episode Naming: The X of Y; usually, but not always, "The <person> of <place>".
In the Past Everyone Will Be Famous: The characters have interactions with several examples of a Historical Domain Character.
In Harmony with Nature: Nubia has a strong connection with animals that is almost magical.
It Was a Dark and Stormy Night: The opening of the short story "'The Five Barley Grains" in The Legionary from Londinium & Other Mini Mysteries starts out the way. Caroline Lawrence said that like Snoopy, she always wanted to started a story with that stock phrase.
Jewish Holidays: Rosh Hashannah, Yom Kippur, Succot and Passover are all featured in the series.
Just a Kid: This is played straight throughout the series. Sometimes the four detectives exploit this to their advantage. Sometimes it is an obstacle that they have to overcome.
Kid Detective: The four main characters are all kids, however Flavia is the primary one that refers to herself as a detective, or detectrix in the Latin.
Killed Off for Real: Aside from a number of minor character's whose death are necessary to create the mysteries, there is Gauis Flavius Geminus and Miriam bat Mordecai.
The Killer Was Left-Handed: The Slave-girl from Jerusalem
Love Potion: Historic examples of what Romans believed to be love potions are featured in The Twelve Tasks of Flavia Gemina.
Love Triangle: Variations on the theme take place in some of the books. Caroline Lawrence seems particularly fond of depicting situations where more than one man is in love with the same woman and she must choose which suitor to marry.
Made a Slave: Nubia starts the series as a slave. Many other children are also kidnapped and enslaved, forming the basis of the plots for The Pirates of Pompeii and The Colossus of Rhodes. The Four Detectives are briefly captured in The Pirates of Pompeii and are going to be sold as slaves. Jonathan is also briefly enslaved in The Assassins of Rome and at the end of The Enemies of Jupiter he uses the brand mark to pose as a slave. Three of the Four Detectives are captured yet again in The Colossus of Rhodes..
Manly Men Can Hunt: Jonathan, Lupus, Aristo and Aristo's friend Lysander hunt on a regular basis.
Matzo Fever: Miriam, to every man she meets that's not related to her.
Meaningful Funeral: Happens in The Gladiators from Capua and The Slave-girl from Jerusalem.
Meaningful Rename: Nubia is really the name that was given by the slave dealers to Shepenwepet when she is made a slave. When she is freed, she decides to keep the name, saying "Nubia can be my new name for my new life."
Meaningful Name: A number of characters have names whose meanings in Latin or Greek reflect their characteristics. Just a few are listed here.
- Lupus, the name of the wild character, means wolf. This is also a partial example of Animal Theme Naming although it does not fit that trope perfectly because Lupus is the only one with an animal name.
- Felix is a very fortunate (both rich and lucky) man, as one might expect from the meaning of his name.
- Marcus Geminus and Gaius Geminus are twin brothers
- Flavia is a fair haired girl.
The Medic: Dr. Mordecai
The Mentor: Dr. Mordecai, Aristo and several other adults play the role to varying degrees.
Mistaken for Cheating: Pliny the Elder and Rectina, in The Secrets of Vesuvius
Mister Big: The head of an illegal kidnapping ring turns out to have dwarvism.
Monumental Battle: Lupus gets into a fight onto of the remnants of the Collosus, in a deliberate Shout-Out to North by Northwest.
Murder by Mistake: In The Fugitive From Corinth Marcus Flavius Geminus is stabbed and almost killed by a person attempting to murder Aristo.
- A beggar boy that was given a tunic by Lupus is thrown into a crocodile pit when he is mistaken for Lupus.
Music for Courage: The Four Detectives play music for refugees in The Pirates of Pompeii.
Mystery Tropes: A wide variety of standard mystery story tropes are used throughout the series.
- Mystery Arc: Most of the stories
- Mystery Fiction: Most of the stories
- Mystery Magnet -Flavia
Mysterious Past: Lupus's origins and the reason he has no tongue are not revealed until several books into the series.

Tropes N though S

Naked on Arrival: Nubia is first shown as a naked slave being prepared for auction.
Patronymic: The books accurately depict the use of patronymics in period cultures. Notable examples are Jonathan ben Mordecai and Mordecai ben Ezrah.
Never Found the Body: Gaius Flavius Geminus dies at sea in a shipwreck. The body is never recoved, however it is strongly implied that he was Killed Off for Real.
Oh My Gods: Pollux!
Long-Haired Pretty Boy: Several slave boys are described this way.
Painting the Medium: THE AUTHOR USES ALL CAPS TO INDICATE THAT LUPUS COMMUNICATES THROUGH WRITING (IN LATIN CAPITAL LETTERS) ON A WAX TABLET
Passing the Torch: Lupus and Threptus. Threptus will become the main character of a spin-off series.
Parental Abandonment: All four of the main characters have Missing Moms. Nubia and Lupus undergo an Orphan's Ordeal and Jonathan and Flavia both have times when their fathers are literally or figuratively distant.
Play-Along Prisoner: When Jonathan has been Chained to a Rock (actually he was tied to a cross) in order to be Fed To The Beasts, the person that ties him up makes the ropes too loose so that he can escape at the right moment. When the beast that is supposed to eat him shows up, it turns out to be a harmless lion that Jonathan already knows. He then Slips The Ropes and climes onto the lion, riding it out of the arena. Those trying to execute him see this as a sign from the gods that he should be spared.
Police Are Useless: Well, not completely useless, but the only thing they seem to be useful for are locking up the criminals that Flavia and friends have identified. Of course, historic Rome did not have anything approaching modern police forces and professional, scientific criminal investigation techniques, so this is probably not far from the truth.
Phone-in Detective: Though obviously there are no phones involved, Flavia does this a few times, most notably in The Legionary from Londinium in which she deduces the location of a treasure hoard from another country. In her introduction Caroline Lawrence calls this trope "an armchair mystery."
Pit Trap: Used in The Beggar of Volubilis to trap peoples that pursuing the main characters.
The Plague: A historical plague that hit Rome in 80 AD is featured in The Enemies of Jupiter.
Plucky Girl: Flavia
Practice Kiss: Flavia has a Practice Kiss with Jonathan.
Pride: Pride of the hubris variety is one of the explicit themes of The Enemies of Jupiter.
Prophetic Dreams: Jonathan has prophetic dreams in several of the books. Flavia has a prophetic dream that forms the basis of The Twelve Tasks of Flavia Gemina. A prophetic dream also plays a major role in The Enemies of Jupiter.
Rags to Riches: Lupus goes from being a begger boy to owning his own ship.
Recounted By the Main Characters: The does not apply to most of the series, but it partially applies to The Roman Mysteries Treasury. The text of the book is written as if it is a report assembled by Flavia Gemina, with her and her friends and family each writing a different chapter on a topic that Flavia assigned to them.
The Roman Empire: The books are set in a well-researched depiction of the Roman Empire.
Romance Arc: Flavia and Nubia both go through a Romance Arc that eventually leads to both of them being married in the last chapter.
- Romantic False Lead
- Romantic Runner-Up
Sadistic Choice: Nubia has the opportunity to free one gladiator from slavery. She has to choose between her brother and her friend Jonathan.
The Scapegoat: Jonathan is blamed for burning of Rome, causing him to become a Condemned Contestant.
Scars Are Forever: Lupus's missing tongue
Secondary Character Title: Most of the book titles, when they refer to a character, refer to a secondary character or groups of characters that are pivotal to the plot but are not one of the series's four main characters.
Sea Stories: Most of the series would not qualify, however The Colossus of Rhodes would. Not only is it about ship voyage through the Mediterranean Sea, but the story also incorporates explicit parallels to one of the Sea Stories of Classical Mythology, namely Jason and The Argonauts.
Settle for Sibling: Marcus Flavius ends up getting married to a sister of his deceased fiancée.
Shark Pool: With crocodiles.
Sherlock Scan: Flavia does this several times, including in The Secrets of Vesuvius and The Legionary from Lodinium.
Shout-Out: A number of them, including:
- "He will live long and prosper
- "A funny thing happened on the way to the forum."
Shrine to the Fallen: The books show the Roman custom of displaying the death masks of ancestors.
Sick and Wrong: This trope could be a rough translation of the Roman concept of "nefas" which is described in The Sirens of Surrentum.
Sidekick: Nubia is described by the author as Flavia's faithful sidekick.
Slave Brand: Jonathon is branded with one in The Assassins of Rome. It continues to cause him trouble in later books.
Slave Liberation: Granting freedom to household slaves was actually common practice among the Romans. There are several examples of slaves being set free, but the most notable one is Flavia freeing her slave girl Nubia, by inviting her to recline at her coach.
- In The Slave Girl of Jerusalem the Roman custom of freeing slaves upon the death of their master is an important plot point.
Snooping Little Kid: Lupus uses his skills at snooping, sneaking and eavesdropping several times throughout the series.
So Beautiful It's a Curse: Miriam laments the fact that she is so attractive that she is always attracting an unwanted level of male interest.
The Speechless: Lupus is upable to speak because his tongue has been cut out.
Show Within A Book: The The Beggar of Volubilis depicts a traveling troupe of actors who end up putting on a play with the Four Detectives. They perform pantomime of the Roman variety, related to but not quite identicle to Pantomime of the modern British variety.
Stranger in a Familiar Land: Nubia in The Scribes of Alexandria gets as far as the borders of her own country, but realizes that she no longer fits into her own country.
Street Urchin: Several examples appear in the series, however the most notable is Lupus, who becomes one of the four main characters.
Starts with Their Funeral: The Gladiators of Capua starts with a memorial service for Jonathan.
Succession Crisis: Part of the plot in The Man from Pomegranate Street, as the result of the death of Roman Emperor Titus.
Sweet Polly Oliver: In The Scribes of Alexandria a girl disguises herself as a eunuch in other to study as in the Library of Alexandria. This leads to a Sweet on Polly Oliver situation with a male scribe. In The Fugitive from Corinth another girl disguises herself as a beggar boy. Flavia and Nubia both disguise themselves as boy at times.

Tropes T though Z

That Man Is Dead: Jonathan takes this on when he becomes a gladiator and adopts a new name.
Tomboy: Flavia, and to a greater degree Diana, are mild tomboys by modern standards but are most especially tomboys by Roman standards.
Team Dad: Marcus Flavius Geminus
Team Mom: Alma acts as a Parental Substitute to Flavia, and to a lesser degree all four of the main characters.
Team Pet: Nipur, Scuto and Tigris are Canine Companions of Nubia, Flavia and Jonathan respectivly.
The Heart- Nubia
This Is My Name on Foreign: Lupus's actual name is Lukos. However, both names simply mean "wolf." This does not follow the trope perfectly, because it is not an alias that Lupus picks for himself.
Translation Convention: Most of the characters are really speaking Latin or Greek, however it is normally depicted in English. When the author intends for a line of dialogue to not be understood by the main characters or the audience, she will say that a certain character said something in a given language rather than reproduce the words the character says.
Tragedy: The characters discuss tragedies and the purpose of tragedies in general, and several Classical Greek tragedies in particular.
Twin Switch: Gaius poses as Marcus in one of the books.
Twofer Token Minority: Jonathan in his family is Jewish and Christian. Of course, being a Christian may not seem to be a minority thing to most modern Western readers, but they are minorities in pagan Rome.
Undignified Death: In one of the short stories, a body is found with its head immersed in a public piss pot.
Unexpected Inheritance: Lupus is the heir to Venalicus when he dies, and gets the slave ship Vespa. The ship is turned into the Delphina and is used to replace the ship that Marcus Flavius lost in tsunami.
Unreliable Expositor: A number of characters state scientific, medical or geographic facts that are now known to be inaccurate, but do correspond to what educated people in the 1st century AD Rome actually believed.
What Could Have Been: There were originally going to be eighteen books in the series, but Caroline Lawrence had to cut the mystery that was to take place in Roman Britain because there was no room on her carefully plotted time-line for the four protagonists to travel there and back again between the historical events that she wanted them to be involved with.
While Rome Burns: Inverted in a big way. Rome literally burns in The Enemies of Jupiter, but the main characters are certainly not fiddling while it happened.
World of No Grandparents: None of the main characters have grandparents take any major role in the story. Most of the grandparents are dead. Given the low life expectancy of this time period, this is highly realistic.
Wrong Guy First: Flavia's first crush is on Publius Pollus Felix who is rich, handsome, charming, witty and charismatic. Unfortunately, he is also married and a Casanova. This results in a lot of Love Hurts feelings.
You Are Grounded: This happens to Flavia in Twelve Tasks of Flavia.
You Are Number Six: Several Roman characters have names based on numbers, such as Sextus and Quintus. However, this does not have the same dehumanizing or secret identity implications it would in modern times, because these were normal real life Roman names.
You Can't Go Home Again: The four detectives and their families can't stay in Ostia at the end, because they are exiled.
You Meddling Kids: The most notable example of this is the ending of The Thieves of Ostia
Your Cheating Heart: A surprising number of examples for a book with a target audience of 8-12 year old children. Felix in The Sirens of Surrentum is revealed to be a serial philander. Also, it is revealed that the mother of one of the main characters ran off with the man she had wanted to marry but could not because of an Arranged Marriage.