Basil's American Tail

A Crossover fan fiction by Surenity, which links The Great Mouse Detective with An American Tail.

The year is 1886. Basil of Baker Street, fresh off of busting Ratigan's latest heist at the British Museum, travels to New York in search of stolen artifacts which he discovered had been sold on the black market to "a feline obsessed with culture". Upon his arrival he's assigned someone from the NYPD to be his body guard, who, as Basil deduces, is actually a woman in disguise, Miss Nellie Brie, a famous undercover reporter who couldn't resist getting the scoop on Basil's latest case. After proving her worth as an assistant to Basil, the two embark on a case that takes them through the corrupt underbelly of New York City, exposing a crime lord, and in the process, even helping a certain lost little boy reunite with his family.

The fan fic, in its complete state (19 chapters in all), can be read on Deviant ART here. A sequel, Olivia Goes West, is currently in progress.

Tropes used in Basil's American Tail include:

Action Girl: Nellie, who proves just as capable a detective as Basil.
Bad Guy Bar: Basil and Nellie sneak into one so they can spy on Cat R. Waul and his gang.
Child-Hater: Perhaps not a hater, but Basil was never very comfortable around children, and expresses his extreme annoyance with Fievel several times throughout the story. Nellie, on the other hand, seems much better with children.
Crossover Ship: Basil and Nellie Brie, eventually.
Culture Clash: Basil just can't understand these American mice and their tendency to run around barefoot and randomly break out in song when there's no way they could have known the lyrics beforehand.
Dark and Troubled Past: Both Basil and Nellie have one, though Basil's is somewhat worse. Nellie's is a mouseified version of the human Nellie Bly's past.
Expy: Nellie Brie is made even more of an expy of the historical Nellie Bly than she was in Mystery of the Night Monster. Lampshaded in the final chapter, when Nellie Bly is mentioned by a human cop.
Fanon: Sherringford being Basil's first name (a trend in many GMD fics due to it being Sherlock Holmes' original name in an early draft).
- Also, Dylan O'Brian, the fanon name for the Irish mouse from the "There Are No Cats in America" song in An American Tail, makes an appearance.
Funetik Aksent: Gussie Mausheimer's Elmuh Fudd Syndwome is the most obvious example, plus anyone with an Irish accent (this being 1880's New York, it shows up a lot).
The Glomp: Fievel gives one to Basil, in almost the same way Olivia did in The Great Mouse Detective, and similar to the one he gives Tony in the movie.
Intrepid Reporter: Nellie.
It's Not You, It's My Enemies: The reason Basil can't bring Nellie to London until he defeats Ratigan. Nellie has her own reasons for not being able to come too, as described below.
I Will Wait for You: Nellie and Basil, being from different worlds, both promise to do this for each other at the end, until Basil defeats Ratigan in London and until Nellie feels she's made New York a safer place to live through her undercover reports.
Last-Name Basis: Basil, who actually prefers it that way.
Massive Multiplayer Crossover: What with Basil, Warren, Cat R. Waul, Cholena and Nellie Brie all appearing in the same story, among many others.
Master of Disguise: Both Basil and Nellie, though Basil sees right through Nellie's disguises (as well as Warren's later).
Mouse World
Police Are Useless: As Nellie was working on exposing before being sidetracked by Basil coming into town.
Running Gag: Basil can't pronounce "Mousekewitz" any better than he could pronounce "Flaversham".
Shared Universe: Not only between The Great Mouse Detective and An American Tail, but managing to work in all four of the An American Tail films, conflicting canons and all.
Sherlock Scan: Basil is good at doing these. Makes Warren's disguise fairly ineffective.
Sleep Cute: Basil and Nellie accidentally fall asleep together while searching for Fievel.
Snooping Little Kid: Fievel, as usual.
Sweet Polly Oliver: Nellie usually disguises herself as a male.
Wicked Cultured: Both Waul and Warren, as it turns out.
Workaholic: Basil, until the end.