1957. Sonny is working on a whaling ship in the South Atlantic, reckoning with the most vicious storms he has ever seen. When he finally returns to his Shetland home to build a life with his wife and young son, the legacy of his time at sea is felt by all of them. In present day Shetland, Jack is an old man, living alone in the cottage where he grew up. One evening, something appears on his doorstep that throws off the rhythm of his solitary existence.