| Director | Kristoffer Nyholm |
|---|---|
| Budget | $5 million |
| Box office | $1.2 million |
Three men begin their six-week shift tending to the remote Flannan Isles Lighthouse. Donald, the youngest, is inexperienced and learning the trade of the lighthouse keeper from James and Thomas. James has a family waiting for him on the mainland. Thomas is still mourning the loss of his wife and children.
After a storm, the men discover a boat, a body and a wooden chest washed ashore. Donald descends the cliffs to check on the man, who appears lifeless. As they haul up the chest, the man awakens and attacks Donald. Donald smashes the man's head with a rock in self-defence.
Thomas is against opening the chest, but does so alone and keeps the findings to himself. Eventually the other two give in to their curiosity and discover several gold bars inside. Urging caution and secrecy, Thomas proposes they dispose of the body, sneak the gold back to the mainland, and lie low for a year before splitting their shares.
Another boat arrives with strangers Locke and Boor, crewmates of the deceased. They interrogate Thomas who claims the cargo has been reported and taken away, as per protocol. The visitors leave but attempt to contact the lighthouse by radio. Thomas and James are unable to respond due to their malfunctioning radio, revealing their lie. The strangers return, circling the island until nightfall. In a violent struggle James manages to strangle Boor and Donald kills Locke, using the woolding. Sensing another intruder outside, the keepers chase him through the darkness and James slashes him with a hook. He is horrified to discover he has killed a young boy, reminding him of his son.
After dumping the bodies into the sea, the three men endure their remaining time on the island despite mounting distrust and tension. James in particular becomes unhinged, secluding himself in the tiny chapel nearby. Donald grows uneasy and insists that he and Thomas leave with the gold. James suddenly reappears, apologising for his behaviour. Once Donald and Thomas let their guards down, James locks Thomas in the pantry and strangles Donald. Thomas breaks free and subdues James.
Finally ready to depart the island, Thomas and James board the dead visitors' boat with the gold. After throwing Donald's body overboard, James admits that he cannot bear to live with his guilt and lowers himself into the water to end his life. He calls for Thomas to help with this last act and Thomas complies by holding James' head under water before sailing on alone.