Gerard Butler (300), Joe Alwyn (Billy Lynn’s Long Halftime Walk) and Peter Mullan (Tyrannosaur) will lead Danish director Kristoffer Nyholm’s (The Killing) psychological thriller Keepers, reports ScreenDaily.

Set on an uninhabited island off the Scottish coast, the film follows three lighthouse keepers (Butler, Alwyn, Mullan) who arrive for their six week shifts. As they settle into their regular routines, they stumble upon an unexpected and life-changing secret.

Sales agent Protagonist Pictures has boarded the project and will introduce to buyers at this week’s American Film Market (AFM) in Santa Monica.

Cross Creek Pictures (Hacksaw Ridge) is fully financing the film, which is set for an early 2017 shoot in the UK.

Andy Evans, Ade Shannon and Sean Marley are producing for Wales-based outfit Mad as Birds with Alan Siegel for G-BASE, Brian Oliver for Cross Creek and star Butler. Jason Seagraves will exec produce and Reg Poerscout-Edgerton will co-produce and is casting.

Aside from directing 12 episodes of the original The Killing series, Nyholm’s credits also include UK miniseries The Enfield Haunting and forthcoming period adventure Taboostarring Tom Hardy for FX and BBC.

Celyn Jones and Joe Bone co-wrote the film’s screenplay.