Shari Lapena's 'The Couple Next Door' plunges readers into a nightmarish scenario when Anne and Marco Conti return home from a dinner party to find their baby, Cora, missing. The police investigation unearths a web of secrets, lies, and betrayals not only within their own marriage but also concerning their seemingly perfect neighbors. As suspicions mount and the truth becomes increasingly elusive, Lapena masterfully builds suspense, questioning how well we truly know those closest to us and the dark depths of human nature. This psychological thriller is a relentless exploration of trust, guilt, and the devastating consequences of one terrible mistake, keeping readers guessing until the very last page.