New York Times bestselling author Margaret Peterson Haddix, the master of cliffhangers, delivers a pulse-pounding mystery perfect for fans of Jacqueline West and Kat Yeh, full of secrets, surprises, and the power of family.One minute theyre there: laughing and having fun at the house next door. The next minute, the teens are gone. Like magic. Marin cant believe her eyes. Who are they? Can anyone e...