Detective Murdoch investigates the death of young woman, Judith Winslow, found on the waterfront at the Toronto Athletic Club. Dr. Grace determines the young woman died from drowning though she was struck on the head before going into the water. She worked as a secretary at a financial firm run by Alvin Storey but had ambitions to be a journalist. According to her roommate Sophia Lucas, she had no enemies. The police soon have a second murder when Ethel Morgan is found dead in a alleyway - also having drowned. A third victim - Virginie Rousseau - is found before Murdoch finds the connection between the three. Emily Grace - champion croquet player for two years running - returns to the athletic club - she was not welcome there once she broke off her engagement - after hearing that Canada will be sending a croquet player to the Paris Olympics.