FanficRecs Amazing continuation of The Raven Chaser film
This fic probably gets my record for the most thorough rereads in the shortest amount of time for an incomplete fic, it's THAT impressive a work. Detective Conan movies are notorious for having much higher stakes and bombastic action compared to canon, and this fic is a marvelous example of what might realistically happen in the aftermath if such a film were to actually be considered part of canon. It also picks up and ties together the plot pieces that were left behind said film. It's an excellent show of writing, portraying two sides of a story weaving in and out of each other before finally converging, with police officers having their own investigation while Conan and his band of acquaintances formulate their plans of action. I honestly can't get over the fantastic usage of characters: Not only do the fan-favorites like Kaitou Kid, Hattori, and Hakuba get to shine, but many characters who are typically left Locked Out of the Loop or Put on a Bus for long stretches of time like Takagi, Sato, Jodie and James also play major roles. I want to specially note that this fic has made me a huge fan of Kansuke Yamato and Yui Uehara, who I previously tended to overlook amongst the series' Loads and Loads of Characters. This is enormously satisfying to read as a Detective Conan fan who wishes more of the cast would interact or get involved in the fight against the Black Organization. I can only pray it gets updated again someday.
FanficRecs Fallout
Seconded! Fallout is THE best Detective Conan fanfiction I've ever read. All the scenes are realistic and emotionally packed. There is also a very convincing, very tense car chase. Although updates are scarce, the chapters are long (about 30 pages long according to the author). It has that interesting Murphy's Law aspect that would appeal to any troper, where everything gets shot straight to hell. Bonus; The author is meticulous and does more research than the movie makers, even pointing out the mistakes of Gin's car design and different types of Porsche.
FanficRecs
Hugely recommend. This is so well researched, so well written, it's everything you could want in a fic. The chapters are long so it gives a lot of content, so don't let the seemingly low chapter count put you off. You'd be seriously missing out. The tension is amazing and a bunch of characters get the chance to shine, not just the usual crew of Conan and Kaito (though of course they have their moments). The Black Org stand out as terrifying and unstoppable in a way they don't always in the official material. I'd go as far as to say this is a must read for any Det Co fan.