At 7 p.m. on 28 December 1879, a violent storm batters the newly built rail bridge across the River Tay, close to the city of Dundee. Ann Craig is waiting for her husband, the owner of a large local jute mill, to return home. From her window Ann sees a shocking sight as the bridge collapses, and the lights of the train in which he is travelling plough down into the freezing river waters.

As Ann manages the grief and expectations of family and friends amid a town mourning its loved ones, doubt is cast on whether Robert was on the train after all. If not, where is he? And who is the mysterious woman who is first to be washed ashore?

In 2015, Fiona Craig wakes to find that her partner Pete, an Australian restaurateur, has cleared the couple's bank account before abandoning his car at the local airport and disappearing. When the police discover his car is stolen, Fiona conducts her own investigation into Pete's background, slowly uncovering dark secrets and strange parallels with the events of 1879.