In Aberdeen, Faber steals a small trawler and sets out to meet the U-boat. Caught by a fierce storm, he is shipwrecked on Storm Island, collapsing near the isolated house where David and Lucy live. Lucy nurses him back to health. Stuck in a loveless marriage to the crippled David, she begins a physical relationship with Faber. David soon discovers both Lucy's infidelity and Faber's FUSAG photos. David confronts Faber, but after a struggle Faber kills David by rolling him off a cliff, and tells Lucy it was another accident. However, she discovers her husband's body and realises the truth.