After a tragic accident claims her young son, a successful London novelist retreats to a remote Scottish coastal village hoping solitude will revive both sanity and creativity. The isolation deepens her grief rather than easing it. During research trips to a nearby lighthouse she meets a mysterious keeper whose warmth disrupts her numb routine. Their sudden intimacy offers brief relief. Soon afterward locals insist the man died years earlier, forcing Rachel to question memory, perception, and whether the haunting presence around her is supernatural or psychological.