Like the ragtag group of ex-soldiers they were playing, the stars of The Predator didn’t know what they were in for, signing up for Shane Black’s 2018 reboot of the franchise—but they were satisfied with where they ended up, and the rapport that developed between them over time.

Approached for the project, actor and comedian Keegan-Michael Key saw that the Predator sequel checked two of the usual boxes—an exciting franchise update and a visionary filmmaker were both on hand. “I’m like, ‘Okay, we’re going to make a Predator movie? Oh, with Shane Black? Okay, I can do that. That sounds good,'” Key said, sitting down today at Deadline’s Toronto Studio, alongside co-stars Thomas Jane, Boyd Holbrook and Augusto Aguilera.

What Key wasn’t expecting was a blockbuster that allowed for ample improv, and a filmmaker responding so quickly to what his actors brought to the table, rewriting entire scenes based on the chemistry that was manifesting before his eyes. “I expected to come in and learn these lines rote, learn them word-perfect, and treat it like canon, treat it like Shakespeare, and he was surprisingly very collaborative,” Key shared.

Appearing (in a rare turn as an actor) as one of the Predator’s early kills in the original 1987 film starring Arnold Schwarzenegger—and thinking over his take on the franchise for some 30 years—Black  approached his Predator film as a mythology-expanding sequel, rather than a revamp of the franchise, centering the action on a dysfunctional group coming together to rally against new stages in the titular alien hunter’s evolution.

While there is certainly plenty of fun and plenty of spectacle at hand in The Predator, the film does have its more serious underpinnings, with its examination of the aftermath faced by those returning home from war. Holbrook’s character, in particular, has a nasty case of PSTD, putting him in contrast to heroes seen in previous Predator films and other major action franchises.

“The ‘80s was all about big guns and big muscles, and we’re going to go kick some ass and stuff—and now it’s like, we’re the consequences of that,” Jane reflected. “It’s 2018 now—we’ve been through a lot of wars. We have a lot of boys coming home, and guess what?”

To hear more from the stars of The Predator, take a look above.

Deadline Studio at TIFF 2018 presented by eOne. Special thanks to sponsor Watford Group, and partners Calii LoveLove Child Social, and Barocco Coffee.