What remains A thriller

In this middling thriller from Walker (American Girl), Det. Elise Sutton is in a Connecticut department store when shots ring out. Near the dressing rooms, she spies an armed 20-something man taking aim at a tall, frightened man. Elise--a cold case investigator--kills the gunman before he can claim a single life, but despite being hailed as a hero, she's wracked with guilt for doing so. The man she saved doesn't give a statement, so Elise seeks him out and is relieved when his account vindicates her actions. She soon discovers, however, that the man started stalking her post-shooting, and nearly everything he told her was a lie, including his name. When he begins threatening Elise's husband, police partner, and daughters, Elise realizes he won't stop unless she makes him. Walker intercuts Elise's first-person-present narration with chapters detailing an investigation into human remains found in a hunting shelter's cremation oven, though the subplot feels awkwardly shoehorned in. And though Elise's stalker is terrifying, her reactions to his escalations strain credibility, blunting the story's impact. Walker has done much better. Agent: Elisabeth Weed, Book Group. (June)