Spoilers for all three “Knives Out” movies follow.

Rian Johnson has proven himself to be a master of the whodunnit with his Benoit Blanc murder mysteries “Knives Out,” “Glass Onion” and “Wake Up Dead Man,” all three of which keep audiences guessing right up until their stunning climaxes, where Daniel Craig’s brilliant sleuth, with valuable assistance from one of the suspects, reveals all. They’re basically star-studded “Columbo” episodes where the how is typically more fascinating than the who, which is a good thing because, three films into the series, Johnson might be tipping his hand just a tad.

Hopefully, you’re reading this article after watching all three movies because I’m about to spoil the dickens out of them.

Though the movies are very different in tone and certainly location, there is a common thread that ties the film’s murderers together. In the first movie, Chris Evans’ Hugh Ransom Drysdale is the assailant of his wealthy grandfather Harlan Thrombey (Christopher Plummer). In movie two, it’s Edward Norton’s tech billionaire Miles Bron who’s guilty of murder. And in the most recent film, we get a two-fer in Jeremy Renner’s Dr. Nat Sharp and Glenn Close’s Martha Delacroix.

What do these characters have in common? Nothing really. The actors, however, are linked by one piece of casting: they’ve all been in Marvel movies.

Evans is obviously Steve Rogers/Captain America, while Norton portrayed Bruce Banner 2008’s “The Incredible Hulk.” We all know Renner is Clint Barton/Hawkeye, while Close played Nova Prime Irani Rael in the first “Guardians of the Galaxy.” Is Johnson, who’s never been associated with a Marvel Cinematic Universe film, trying to tell us what he thinks of the movie brand?

Of course, Johnson is no stranger to franchise filmmaking himself, having directed “Star Wars: Episode VIII – The Last Jedi,” so it’s unlikely he holds any ill will for superhero movies. I also doubt this is intentional in any way because, let’s face it, loads of working actors have found their way into the MCU over the years. When casting one of these mysteries, Johnson might have a harder time finding actors who haven’t been in a Marvel movie than those who have.

Nevertheless, when he gets around to making the fourth film in the series, you might want to take note of which actors have spent some time in spandex. They might just have murder on their mind. This is why the next “Knives Out” installment should have a cast solely of Craig and dogs.