In London, researching for her ongoing series on important women in British history, Aventurine Morrow finds herself embroiled in her friend Linny Breedlove's marital troubles. When the body of Peter Breedlove's ex-wife turns up in the Grand Union Canal, Linny enlists Aventurine's aid in attempting to discover the identity of the murderer and clear Peter's name. With the help of her nephew and his partner, and that of DCI Burroughs?who is trespassing on another police force's patch?Aventurine ferrets out a number of likely suspects, some of them uncomfortably close to her. But faced with the multiple possible motives for the killing, Aventurine must find a balance between friendships and the truth.