'Castle' Finale: What's Next for Nathan Fillion and Stana Katic

Fillion already has a BIG project!

— -- Don't stress "Castle" fans. Even though your favorite show might be over, your favorite stars Nathan Fillion and Stana Katic will be back very soon.

Fillion, 45, is already filming "Guardians of the Galaxy 2." Yes, Fillion will star alongside Chris Pratt, if he weren't already awesome enough by himself.

Fillion will be Simon Williams, aka Wonder Man, who has a long history in the Marvel Universe, dating back to the early 1960s. The interesting part is Wonder Man, a former Avenger, was featured in the Civil War books. So, maybe that's a tie in and a sign of future Marvel films to come for Fillion.

Wonder Man's powers are simple: He's super strong and can manipulate ionic energy. He was born in New Jersey, a tad bit away from Alberta, Canada, where Fillion was born, but who cares, right?

"Guardians 2" is set to hit theaters on May 5, 2017.

Katic, on the other hand, has even more coming out this year.

The film "Lost in Florence" will see her team up with Brett Dalton. Yes, the guy from "Agents of S.H.I.E.L.D." The Marvel connections don't stop!

The IMDb descriptions reads, "A heartbroken American in Florence gets involved in a dangerous local sport -- and with an alluring local woman." That movie is out in September.

The 38-year-old also appears in another movie, "Sister Cities," alongside Amy Smart, Michelle Trachtenberg and "Pretty Little Liars" star Troian Bellisario.

This movie is a bit more serious, as "four estranged sisters reunite after their mother's alleged suicide," according to IMDb.

The moral of this story is that Fillion and Katic may not be on "Castle" anymore, but you haven't seen the last of these stars.