Liv Travers, the narrator of this Highsmithian psychological thriller from British author Mayhew (Impossible Causes), has never had close friends, so she's elated to bond with fellow suburban moms Beth and Binnie. Liv's husband, Pete, and young daughter, Ivy, get on well with the women's families, so the bunch gathers whenever possible. It's idyllic--until Beth's wealthy, type-A coworker, Ange, joins the fold, and cheap, casual get-togethers become pricey London outings. Liv and Pete incur massive debut to avoid exclusion, but Liv can't shake the sense that Ange is trying to sideline her--a suspicion that intensifies when Ange proposes a group trip to Corfu, Greece. Liv drains her savings to join in and then starts scheming, determined to beat the manipulative interloper at her own game. Mayhew sets the bulk of her tale on Corfu, using frequent flashbacks to color in the cohort's shared history. Though the supporting cast feels hastily sketched, Liv is a fully developed character whose palpable anxiety, desperation, and rage drive the diabolical plot to a calamitous conclusion. Lucy Foley fans, take note. Agent: Louise Lamont, LBA Books (U.K.). (June)