May 1947 in St. John's, a woman is brutally murdered in her bath. In the same neighbourhood, in 1943, a young American soldier was also murdered, a crime that was never solved. Two murders, four years apart. One killer or two? Inspector Eric Stride of the Newfoundland Constabulary uncovers a complex web of evidence and circumstance, following a trail that goes back more than twenty years. Along the way, Stride finds that his own life is in danger. Undertow is set against the backdrop of wartime and post-war Newfoundland, in a time of social and political upheaval.