汤姆（迈克尔·法斯宾德 Michael Fassbender 饰）是曾经在前线卖过命的退伍军人，如今，他带着妻子伊莎贝尔（艾丽西亚·维坎德 Alicia Vikander 饰）前往位于澳大利亚西部的一座小岛上，成为了那里的灯塔守灯人。小岛上离群索居的生活让汤姆和伊莎贝尔之间的感情越发要好，两人在喜悦之中等待着伊莎贝尔腹中的孩子慢慢长大。 　　令夫妻两人没有想到的是，一场意外令伊莎贝尔流产了，孩子的逝去令伊莎贝尔陷入了绝望之中。一天，一艘船被海浪冲上了岸，船上出了有一具男性的尸体外，竟然还有一个婴儿。欣喜若狂的伊莎贝尔恳求汤姆同意她收留并抚养这个孩子，虽然这种做法有违汤姆的原则，但他还是答应。A war weary man takes a job as a lighthouse keeper on an island for the solitude. He meets a beautiful young woman and they eventually marry. One day they see a small dingy with an infant and man inside floating in the ocean. They rush to rescue them only to find the man is dead. They struggle over the decision to report it and whether to keep the baby. It's only years later that they discover that the child still has a mother looking for her.