Kind, quiet Clemmie Lakefield, the protagonist of this uneven mystery from Cooney (Before She Was Helen), is everyone’s friend at the Sun City retirement community—she gives rides, hosts Bible studies, prepares snacks, and provides a shoulder for neighbors to cry on. She’s shocked when her friend Muffin Morgan insists they leave church one Sunday because Muffin spots someone from her past who she’s afraid might want her dead. Flash back to 1964, when newly married Muffin prevented her husband and three of his friends from lynching journalist MacBurton Ward, who was in their South Carolina town to write about segregation policies. Muffin got MacBurton to safety, then disappeared, changed her name, and established a new life. Clemmie has a shady past herself, but doesn’t take Muffin’s concerns too seriously—until somebody turns up dead. The timeline alternates between the present and the ’60s, never generating enough tension in either setting, and Cooney’s characters are mostly thin and unconvincing. A gut-wrenching final chapter compensates only in part for a shallow plot throughout. Cooney makes a valiant attempt to tackle the South’s history of racial bigotry but comes up short. Agent: Kerry D’Agostino, Curtis Brown. (May)