Bloodroot: A Martha’s Vineyard Mystery

In Riggs’s agreeable 12th Martha’s Vineyard mystery (after 2012’s Poison Ivy), someone uses arsenic—easily available on the island—to poison the wealthy and unpleasant Mildred Wilmington while she’s at the dentist. The dental clinic is a hotbed of lust, jealousy, and greed, but also under suspicion are the four grandchildren she helped raise and who are expected to do very well financially now that the old lady is gone. Since the police are busy preparing for a visit by the U.S. president, it’s up to 92-year-old deputy Victoria Trumbull to investigate. Fortunately, most people are willing to confide in Victoria, which helps her sort through the mess. Meanwhile, Lockwood, the duplicitous and dangerous former husband of Victoria’s granddaughter Elizabeth, shows up on the Vineyard. Despite scads of evidence that Lockwood is no good, Victoria welcomes him. Maybe it’s because she needs his help to unmask the killer. He doesn’t contribute much to the story otherwise. Agent: Paula Munier, Talcott Notch Literary Agency. (May)