A CrossOver fan fiction by Tropers/{{Surenity}}, which links ''Disney/TheGreatMouseDetective'' with ''WesternAnimation/AnAmericanTail''.

The year is 1886. Basil of Baker Street, fresh off of busting Ratigan's latest heist at the British Museum, travels to UsefulNotes/NewYorkCity in search of stolen artifacts which he discovered had been sold on the black market to "[[WickedCultured 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, 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 Website/DeviantArt [[http://surenity.deviantart.com/gallery/36455407 here]], or on Website/FanFictionDotNet [[http://www.fanfiction.net/s/8744855/1/Basil-s-American-Tail here]]. The Website/FanFictionDotNet version has some differences, whereas scenes and lines of dialog taken directly from the script of ''WesternAnimation/AnAmericanTail'' were removed or at least altered at the urging of the website's moderators. Surenity has also completed two sequels, ''FanFic/OliviaGoesWest'' (which is complete) and ''The Great Mouse Reporter'' (which is still being written). ''Olivia Goes West'' is also available at both [[http://surenity.deviantart.com/gallery/37317746 DeviantArt]] and [[http://www.fanfiction.net/s/8772062/1/Olivia-Goes-West fanfiction.net]].



* ActionGirl: Nellie, who proves just as capable a detective as Basil.
* TheAlcoholic: Honest John, as in the movies.
* AlternateUniverseFic: Lampshaded when [[spoiler: Basil [[ThinkNothingOfIt declines taking credit for reuniting Fievel with his family]], stating that he believes it all would have worked itself out on its own without his intervention, which it did in the actual film.]]
* BadGuyBar: Basil and Nellie sneak into one so they can spy on Cat R. Waul and his gang.
* TheBigRottenApple: In more detail than the ''An American Tail'' films.
* {{Bowdlerise}}: The author was forced to create a more copyright-friendly version for Fanfiction.net, though aside from altered scenes and dialog it reads mostly the same, and the majority of the chapters were unique enough to require no change at all. The Mouse of Minsk scene is where it needed the most alterations.
* ChildHater: 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.
* CrossoverShip: Basil and Nellie Brie, eventually. [[invoked]]
* CultureClash: Basil just can't understand these American mice and their tendency to [[BarefootCartoonAnimal run around barefoot]] and randomly break out in song when there's no way they could have known the lyrics beforehand.
* DarkAndTroubledPast: 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 Literature/SherlockHolmes' original name in an early draft). [[invoked]]
** 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.
* FunetikAksent: Gussie Mausheimer's ElmuhFuddSyndwome is the most obvious example, plus anyone with an Irish accent (this being 1880's New York, it shows up a lot).
* TheGlomp: Fievel gives one to Basil, in almost the same way Olivia did in ''Disney/TheGreatMouseDetective'', and similar to the one he gives Tony in the movie.
* ImpersonatingAnOfficer: Nellie Brie not only disguises herself as a male cop but actually completes the police academy while on an undercover report, one which was aborted once she got wind of an even bigger story in Basil coming to town. The disguise doesn't fool Basil for a second though.
* IntrepidReporter: Nellie.
* ItsNotYouItsMyEnemies: [[spoiler: The reason Basil can't bring Nellie to UsefulNotes/{{London}} until he defeats Ratigan. Nellie has her own reasons for not being able to come too, as described below.]]
* IWillWaitForYou: [[spoiler: 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.]]
* LastNameBasis: Basil, who actually prefers it that way.
* MassiveMultiplayerCrossover: What with Basil, Warren, Cat R. Waul, Cholena and Nellie Brie all appearing in the same story, among many others.
* MasterOfDisguise: Both Basil and Nellie, though Basil sees right through Nellie's disguises (as well as Warren's later).
* MouseWorld
* PoliceAreUseless: As Nellie was working on exposing before being sidetracked by Basil coming into town. Honest John flat out tells Basil the police are useless against Warren when he and Nellie begin to suspect Warren as the culprit.
* RunningGag: Basil can't pronounce "Mousekewitz" any better than he could pronounce "Flaversham".
* SharedUniverse: Not only between ''Disney/TheGreatMouseDetective'' and ''WesternAnimation/AnAmericanTail'', but managing to work in all four of the ''An American Tail'' films, conflicting canons and all.
* SherlockScan: Basil is good at doing these. Makes Warren's disguise fairly ineffective.
* SleepCute: [[spoiler: Basil and Nellie accidentally fall asleep together while searching for Fievel.]]
* SnoopingLittleKid: Fievel, as usual.
* TheStationsOfTheCanon: Variant--dialogue from all four ''WesternAnimation/AnAmericanTail'' movies are often quoted exactly as is, causing concern with [=Fanfiction.net's=] moderators.
* SweetPollyOliver: Nellie usually disguises herself as a male.
* TwiceToldTale: The events from ''An American Tail'' are happening in the background as Basil works on his case, [[spoiler: only for him to become personally involved in them once he and Nellie are captured by Warren at the same time Fievel is]].
* WickedCultured: Both Waul and Warren, as it turns out.
* {{Workaholic}}: Basil, [[spoiler: until the end.]]