You have to hand it to Marvel. They always have a surprise up their sleeve, and sure enough, sources close to Avengers 4 have confirmed to Collider that 13 Reasons Why star Katherine Langford has joined the superhero sequel, though her role remains under wraps.

TheWrap broke the intriguing casting news on Friday afternoon, reporting that Langford has already shot her scenes for the big-budget blockbuster. It's unclear whether she's playing a hero, a villain, or perhaps a younger (or older?) version of a character we've already met. Either way, the actress finds herself in good company, considering Robert Downey Jr.'s Iron Man, Chris Evans' Captain America and Chris Hemsworth's Thor were among the heroes who survived The Snap.

Infinity War helmers Anthony and Joe Russo return to direct from a script by Christopher Markus and Stephen McFeely, and Kevin Feige is once again the sole credited producer on the new Avengers movie, which remains without an official title -- at least, it hasn't been reported yet. This time around, Brie Larson's Captain Marvel will be part of the action, so who knows how she'll affect the Avengers' dynamic.

No matter how small Langford's role may ultimately prove to be, her association with a billion-dollar franchise is a boon for her career. The 22-year-old is coming off a Golden Globe nomination for 13 Reasons Why, and while she won't be involved in the third season of that show, she is staying in business with Netflix, having landed the lead in the streamer's King Arthur series Cursed. She'll play a heroic young woman who eventually becomes the Lady of the Lake.

Langford recently appeared opposite Nick Robinson in the acclaimed coming-out drama Love, Simon, and she just wrapped Brian Duffield's high school movie Spontaneous, which co-stars Charlie Plummer. Langford is represented by WME, Brillstein Entertainment Partners and Independent Management Company in Australia. Marvel had no comment regarding her casting.

Disney will release Avengers 4 on May 3, 2019. There are no other movies slated for release that weekend, if you can believe it.