River levels are high in Portland when a woman walking her dog comes across the skeleton of a young black man, murdered over fifty years ago. Journalist, Susan Ward investigates. Meanwhile, Detective Archie Sheridan and his team have turned their attention to child-killer Ryan Motley, trained by the notorious Gretchen Lowell. The task force must pursue a series of mysterious clues from Gretchen, one of which leads to a Vanport flood survivor, who happens to be the grandfather of a murdered child. Then, when another child is found murdered, Archie's investigation takes on a new urgency.