In a world created by Harry Potter scribe J.K. Rowling, even the actors get lost in the magic of “Fantastic Beasts and Where to Find Them.”

“The job we have to do is make it seem natural— you have to ignore your sense of wonder watching it,” says actress Katherine Waterson in a newly released behind-the-scenes featurette. She portrays Porpentina Goldstein opposite Eddie Redmayne in the new film written by Rowling.

“It’s incredibly exciting,” adds director David Yates. “We’re working directly with J.K.—it’s her first screenplay.”

“Fantastic Beasts and Where to Find Them” sees Redmayne in 1926 New York City as Newt Scamander, a magizoologist who makes a layover in the Big Apple, but things go wrong when he opens his briefcase and some of his magical creatures escape.

“This one catalyst sets in motion an insane amount of events that cause chaos,” says Redmayne. “It’s like imagination taken to the extreme.”

Colin Farrell, Ron Perlman, Dan Fogler, Alison Sudol, Ezra Miller, Samantha Morton, Gemma Chan, and Jon Voight also star in the film that takes place within the Harry Potter universe ahead of Potter’s birth.

“Fantastic Beasts and Where To Find Them” opens on November 18, 2016.