Frey and Rafi are inseparable.... two edges of the same knife. But Frey's very existence is a secret. Frey is Rafi’s twin sister - and her body double. Their powerful father has many enemies, and the world has grown dangerous as the old order falls apart. So while Rafi was raised to be the perfect daughter, Frey has been taught to kill. Her only purpose is to protect her sister, to sacrifice herself for Rafi if she must.

In the Society, Officials decide. Who you love. Where you work. When you die. Cassia has always trusted the Society’s choices. And when her best friend appears on the Matching screen, she is certain he’s the one - until she sees another face flash for an instant before the screen fades to black. Now she is faced with impossible choices: Between Xander and Ky, between the only life she’s ever known and a path no has dared to follow...between perfection and the truth.

Spencer covets her sister's boyfriend. Aria's fantasizing about her English teacher. Emily's crushing on the new girl at school. And Hanna uses some ugly tricks to stay beautiful. But they've all kept an even bigger secret since their friend Alison vanished.

In Beatrice Prior's dystopian Chicago, society is divided into five factions, each dedicated to the cultivation of a particular virtue - Candor (the honest), Abnegation (the selfless), Dauntless (the brave), Amity (the peaceful), and Erudite (the intelligent). On an appointed day of every year, all sixteen-year-olds must select the faction to which they will devote the rest of their lives. For Beatrice, the decision is between staying with her family and being who she really is - she can't have both. So she makes a choice that surprises everyone, including herself.

In Sloane’s world, true feelings are forbidden, teen suicide is an epidemic, and the only solution is The Program. Sloane knows better than to cry in front of anyone. With suicide now an international epidemic, one outburst could land her in The Program, the only proven course of treatment. Sloane’s parents have already lost one child; Sloane knows they’ll do anything to keep her alive. She also knows that everyone who’s been through The Program returns as a blank slate. Because their depression is gone - but so are their memories.