"A twisty, whip-smart debut thriller, as electrifying as the #1 New York Times bestseller The Girl on the Train, about impending motherhood, unreliable friendship, and the high price of keeping secrets. Helen's idyllic life--handsome architect husband, gorgeous Victorian house, and cherished baby on the way (after years of trying)--begins to change the day she attends her first prenatal class and meets Rachel, an unpredictable single mother-to-be....