When Scottie realises she may never become a mother, she flees to the remote North Atlantic archipelago of St Hia. Lashed by storms and far from anywhere, the islands are dangerous. Many have been lost to the ferocious tides known as the Hollow Sea – and local folklore warns that St Hia was once the home of a monster. Her name was Thordis, and when she was unable to bear children, she was driven to a terrible act . . . The islanders warn newcomers against examining the past, but Scottie can’t look away from Thordis’ story. Could St Hia’s troubled history hold the key to Scottie’s future?