Tally lives in a world where your 16th birthday brings aesthetic perfection: an operation that erases all your flaws, transforming you from an "Ugly" into a "Pretty". She is on the eve of this important event and cannot wait for her life to change. As well as guaranteeing supermodel looks, life as a Pretty seems to revolve around having a good time. But then she meets Shay, who is also 15 - but with a very different outlook on life.

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.

"Ninety-five days, and then I'll be safe. I wonder whether the procedure will hurt. I want to get it over with. It's hard to be patient. It's hard not to be afraid while I'm still uncured, though so far the deliria hasn't touched me yet. Still, I worry. They say that in the old days, love drove people to madness. The deadliest of all deadly things: It kills you both when you have it and when you don't."

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.

One minute, sixteen-year-old Zoey Redbird is a normal teenager dealing with everyday high school stress: her cute boyfriend Heath, the school's star quarterback who suddenly seems more interested in partying than playing ball; her nosy frenemy Kayla, who's way too concerned with how things are going with Heath; her uber-tough geometry test tomorrow. The next, she's Marked as a fledgling vampyre, forcing her to leave her ordinary life behind and join the House of Night, a boarding school where she will train to become an adult vampyre.