The Cellar by Natasha Preston

The #1 New York Times bestseller! A gripping, ripped-from-the-headlines, twisty psychological thriller from the New York Times bestselling thriller author Natasha Preston! Summer is trapped in a cellar with the man who took her-and three other girls: Rose, Poppy, and Violet. His perfect flowers. His family. But flowers can't survive long cut off from the sun, and time is running out. . .