When Benedict Cumberbatch and Robert Downey Jr. came together for Avengers: Infinity War, fans were hoping for a “No sh*t, Sherlock” joke to turn up somewhere, as a nod to both actors having portrayed the Great Detective. As we know, that didn’t happen, but maybe there’s a good reason for that. Maybe the common phrase doesn’t exist in the MCU because Sherlock Holmes isn’t a fictional character. Rather, he’s actually a real person in the Marvel universe.
The rights to the crime-solving sleuth have been pretty complicated over the years, but essentially he’s public domain, so comic book companies have been able to insert the literary character into their universes now and again. DC Comics has probably made the more prominent use of Sherlock over time, with Batman teaming up with the other World’s Greatest Detective on occasion. But he’s also knocking around the Marvel world, too.
Specifically, in 1976 the company published a two-part adaptation of The Hound of the Baskervilles as part of their Marvel Preview anthology series. Perhaps as a bit of cross-comic promotion, a bunch of superheroes started mentioning Sherlock around this same time. Spider-Man, for instance, once quoted his “once you’ve eliminated the impossible, whatever remains, however improbable, must be the truth” catchphrase.
Then, in 2007, a Marvel atlas confirmed Holmes was real in the Marvel universe by referring to him as “the UK’s most renowned private detective.” Furthermore, a Handbook reveals that MI-6 agent Clive Reston is a distant descendant. Maybe, in the MCU, either – or even both – Stephen Strange or Tony Stark are vaguely related to him as well. They both possess Holmes’ genius intellect and eccentric personality, after all.
Obviously, that might be a bit of a stretch, but it is a fact that Sherlock Holmes lived in the Victorian era in the Marvel world. So, with the help of time travel, it’s not too crazy to suggest that the Avengers could meet him in the MCU.