After more than a year of rumors, about everything from casting to influences to plot, Fox's X-Men spinoff The New Mutants begins principal photography today in Boston.

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Director Josh Boone (The Fault in Our Stars) made the start of production official with a photo of a custom clapperboard presented to him by cinematographer Peter Deming depicting the cast and (slightly modified) logo of Growing Pains. In addition to being a popular 1980s television sitcom, "Growing Pains" is the working title of The New Mutants.

Gag gift from @peter_deming We start shooting tomorrow! Wish us luck! #newmutants #xmen

A post shared by Josh Boone (@joshboonemovies) on

The film is thought to draw inspiration from “The Demon Bear Saga,” the influential Marvel Comics storyline by Chris Claremont and Bill Sienkiewicz in which the teenage students of Charles Xavier’s School for Gifted Youngsters are isolated by a freak snowstorm and forced to overcome their own differences to save themselves and their teammate Danielle Moonstar from a demonic bear that killed her parents.

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Characterized by Boone as “a full-fledged horror movie set within the X-Men universe,” the film diverges from the comic-book source material, with the young mutants not students of Charles Xavier but instead teens held against their will in a secret facility.

Arriving April 13, 2018, The New Mutants stars Maisie Williams (Game of Thrones) as Wolfsbane, Henry Zaga (13 Reasons Why) as Sunspot, Charlie Heaton (Stranger Things) as Cannonball, Anya Taylor-Joy (Atlantis) as Magik, Blu Hunt (The Originals) as Danielle Moonstar and Alice Braga (Queen of the South) as Dr. Cecilia Reyes.