Haunted by his experience in World War I, Tom Sherbourne takes his young wife Isabel to the most distant place he can find - a lighthouse island a half day's trip from the Australian coast. After suffering three miscarriages, Isabel is overcome when Tom discovers an open boat with a live baby and a dead man on the island's shore. Wanting to please his wife despite his profound misgivings, Tom doesn't report the child to the authorities, a decision that will gradually eat away at their relationship. And when the truth comes out, Tom is forced once again to make an impossible decision.