Librarian Greer Hogan is on hand to celebrate her friend Sarah Whitaker's nuptials at the Whitaker summer home on scenic Mirror Lake in the town of Lake Placid. But Greer has an ulterior motive, hoping to find information that could reopen the investigation into her husband's murder. When a shady employee of the Whitaker family turns up dead in the lake, Greer begins an investigation—her second, after The Unkindness of Ravens—and finds the suspect list is as long as the guest list, while the killer remains close at hand.