Gerard Butler, Peter Mullan, and Joe Alwyn will star in the psychological thriller “Keepers” with Cross Creek Pictures on board to fully finance.

Production company Mad as Birds is planning for an early 2017 shoot in the U.K. Protagonist Pictures will launch foreign sales during the American Film Market, which opens Wednesday.

TV director Kristoffer Nyholm will helm “Keepers” from a script by Celyn Jones and actor/writer Joe Bone.

“Keepers” is set on an uninhabited island 20 miles from the Scottish coast as three lighthouse keepers arrive for their six-week shift. They stumble upon something that isn’t theirs to keep, triggering a tense battle for survival as personal greed replaces loyalty amid isolation and paranoia.

Producers are Andy Evans, Ade Shannon, and Sean Marley for Mad as Birds; Butler and Alan Siegel for G-Base; and Brian Oliver for Cross Creek Pictures. The project was brought to Cross Creek by Jason Seagraves, who is executive producing.

It was also recently annouced that Butler will star again as Secret Service agent Mike Banning in “Angel Has Fallen,” the third film in the “Fallen” franchise comprised of “Olympus Has Fallen” and “London Has Fallen.” That project is also selling at AFM.

Mullan’s credits include “Tyrannosaur,” “War Horse,” and “Trainspotting.” Alwyn stars in Ang Lee’s “Billy Lynn’s Long Halftime Walk.”

Nyholm directed “The Killing” from Denmark’s DR, the U.K. miniseries “The Enfield Haunting,” and the upcoming period adventure “Taboo,” starring Tom Hardy for FX and BBC. Cross Creek’s credits include “Hacksaw Ridge” and “Black Mass.”

CAA, which represents Butler, Alwyn, and Nyholm, will co-represent North American rights. Butler is also represented by Alan Siegel Entertainment; Alywn by Independent Talent Group; and Nyholm by United Agents. Mullan is repped by Markham, Froggatt and Irwin.