In the mid-1970s, the North Sea oil boom is in full swing and there is work for all.Though Catherine Williams's children are adult and all four have oil-related jobs, she is not happy with the upheaval the oil industry has caused and believes that Davy Jones will demand payment from those who rob his locker, not only with oil spills, but also with men's lives. Immigrant workers flood in and when one such family comes to Deepdale, the valley in Shetland where Catherine lives, her eldest son, Robbie, falls for and secretly marries the daughter.The pair then move to Aberdeen where Robbie gets work on a drilling rig.But, having been persuaded to give up the idea of fishing for a living, will Robbie be any safer on a rig than in a fishing boat?