Belly of the Whale

"''"Tell me, who gives a good goddamn? ''You’ll never get out alive! ''Don’t go dreaming, don’t go scheming ''A man must test his mettle ''In a crooked ol' world ''Starving in the belly, starving in the belly Starving in the belly of a whale!""

- Tom Waits, Starving in the Belly of a Whale

This, as denoted in The Hero with a Thousand Faces, is the conclusion of the Initiation, the first phase of Hero's Journey: "The hero, instead of conquering or conciliating the power of the threshold, is swallowed into the unknown, and would appear to have died." There is no turning back from this point. This is The Hero's point of no return where he resigns himself to the difficult task ahead. Forward march to the Road Of Trials!

It may not be entirely pleasant—there's a reason Campbell compares it with dying. It is often the moment of greatest personal danger for the hero. The Hero can move forward by defeating the Threshold Guardians, but also by being destroyed by them.

For tropes about actual stomachs, try Fantastic Voyage Plot, Swallowed Whole, Ribcage Stomach, or Womb Level.

Anime and Manga

 * The battle in the Cathedral in Claymore, Clare comes close falling and becoming a Youma herself, but ultimately pulls back and from that point on is all but immune to turning.
 * In Chrono Crusade after the events on the "Marionette Train", when the True Companions are sent down the path towards Aion.
 * After  in Tengen Toppa Gurren Lagann, Simon falls in despair and is functionally useless until.

Films -- Animated

 * Like the Biblical story of Jonah, the title character in Pinocchio literally heads into a whale's belly, in order to rescue his father Geppetto.

Films -- Live-Action

 * Anakin's was when he travelled to Coruscant and became determined to become a Jedi, which set him off on his course.
 * And Luke's was when he boarded the Death Star.

Literature

 * CS Lewis's The Lion, the Witch and the Wardrobe: When the Pevensies resolve to stay in Narnia and find Mr. Tumnus instead of returning home, which sets them on the road to save the world.
 * The Voyage of the Dawn Treader: Leaving the Lone Islands
 * The Silver Chair: Eustace and Jill being dropped off by the owls with their Guide, Puddleglum, literally at the start of the literal Road of Trials.
 * In The Book of Three of the Prydain Chronicles this corresponds to Taran's imprisonment in Spiral Castle.
 * In The Wheel of Time, Rand must enter a series of archways to learn the history of  If he stops or turns back at any point during this journey, he will never return.
 * In Tad Williams' Memory, Sorrow, and Thorn, Simon's first journey beneath the tunnels of the Hayholt on the heels of his mentor's Heroic Sacrifice is the point where his journey becomes irrevocable. It also includes the literal metaphor of being "swallowed up" by the earth, followed by his emergence, alone, starving, and companionless.
 * Cleanly marked in Harry Potter and the Philosopher's Stone: when Harry is on the Hogwarts Express, he thinks, "He didn't know where he was going... but it had to be better than what he was leaving behind."
 * In the Whateley Universe, it's the moment when Ayla Goodkind leaves the 'normal' world and rides into Super-Hero School Whateley Academy. Given that 'Goodkind' means 'mutant-hating enemy' in this world, it's pretty much like someone named Hitler going to a university in Jerusalem.
 * In Neverwhere, the Ordeal that Richard goes through. Other characters note that he seems more mature after passing it.

Religion, Mythology, and Folklore

 * The Biblical story of Jonah in the belly of the whale, where Jonah had no choice but to accept God's plans for him, is the Trope Namer (although the Hebrew word used is fish "דג" NOT whale "לִוְיָתָן").
 * In The Odyssey, after Ulysses/Odysseus is the sole survivor of a shipwreck and ends in Calypso's island.
 * Arguably long before that. Since the time spent on Calypso's island is spent in the company of a bevy of beautiful women who want nothing more than to keep him there. The Belly of the Whale for Odysseus is pretty much the moment Agamemnon drafts him into the Trojan War; his life goes downhill from there for the next TWENTY YEARS (10 at war with Troy, 10 trying to get home but with a sizable chunk of time on Calypso's island). Looking at the events of the Odyssey, the moment of hubris in which infuriates Poseidon would probably count.

Video Games

 * Final Fantasy IV's Belly of the Whale is when Cecil is shipwrecked and washed up, all alone, near Mysidia, a city he had attacked and plundered before the start of the game. He has no choice now but to walk the road of atonement.
 * In Baten Kaitos, after the first big Wham! Episode, Xelha finds herself locked up alone in the Imperial Fortress. It's only with that she escapes. And more literally, Baten Kaitos is a star in the Cetus constellation. Yes, it is the belly of the whale.
 * The Legend of Zelda has one for nearly every Link.
 * In A Link to the Past, this comes when he rescues Zelda from Agahnim and becomes a fugitive.
 * In Ocarina of Time, when the Great Deku Tree dies and Link must leave the forest.
 * And later when Link is sealed in the Sacred Realm for a seven-year coma, only to awaken to a Crapsack World in which he first thing he sees is a ReDead.
 * In The Wind Waker, when the pirates first drop Link off at the Forsaken Fortress.
 * Arguably it's immediately after his defeat at the Forsaken Fortress. When he's sent to the fortress, he's still an overconfident kid. After he was tossed into the ocean and rescued, THAT was when he wised up to what he really needed to do.
 * In Twilight Princess, when Link finds himself turned into a wolf and locked in the twilit Hyrule Castle.
 * In Majora's Mask, after the Happy Mask Salesman has taught him the Song of Healing and given him his quest.

Web Comics

 * In Tower of God, the secret plot of Headon and Yu Han Sung requires 25th Baam to disappear from the face of the earth and the eyes of King Zahard. Apparently, it was most effective when he was killed by the person he was looking up to and searching for just when everybody thought it would be just fine. Not only is this a staged death, it is the final sladgehammer stroke that destroys Baam's innocence and replaces it with emotional emptiness.
 * In Gunnerkrigg Court, this moment comes in chapter 7, when Antimony sees Robot S13 on the bridge and rushes out to help, knowing that she'll get in trouble for it. She then gets pushed off the bridge and spends the night trapped in the gorge.
 * In The Inexplicable Adventures of Bob, this happens to Bob in his very first story arc, when he is swallowed by a space monster. Fortunately, Earthlings turn out to be indigestible, and he punches the stomach wall until the monster upchucks him. More recently, he has lampshaded that his survival there was pure luck, and his way of getting out was just inspired by Pinnochio.

Western Animation

 * Avatar: The Last Airbender: In "The Southern Air Temple," after Zuko's attack on the Southern Water Tribe forced Aang to accept his identity as the Avatar, Aang realizes "I really am the last Airbender," and he becomes aware of the danger of the Avatar State.