When young widow Eilis Lawlor disappears in the middle of the night, with her two little children asleep in their beds, it is a chilling case for Detective Lottie Parker. Since her husband's tragic death, Éilis is all her children have, and when Lottie sees Éilis's house keys and phone still lying on the kitchen counter, she is terrified for the vulnerable mother's safety. Then Éilis's broken body is found by a nearby lake, wrapped in an unfamiliar yellow dress, her mouth sealed with duct tape - and Lottie's worst fears are confirmed. Someone wanted this beautiful widow dead. Desperate to find the person behind this brutal crime, Lottie discovers that Éilis was a member of a support group for widows. And when Jennifer, a close friend of Éilis's from the group, is found on a rubbish heap, wrapped in a yellow dress, Lottie vows to get justice. Lottie dives into Jennifer's past, and learns that she had lived a reclusive life since her husband died. She hadn't been seen at work for months and had sheltered inside her immaculate home, only emerging for meetings with the group. But when Lottie questions the other women about Jennifer's isolation, they claim to know nothing. Lottie is certain that the remaining widows are hiding something. Can she uncover the truth before another innocent life is lost?