Spoilers!! This post contains spoilers!
This book takes place about 6 months after the apocalypse. People started turning into rapid, zombie-like vampires that everyone refers to as Ticks. Apparently they find teenager blood more appealing and are repulsed by pregnancy hormones. Teens are sent to "farms" on college campuses where they live in safety from the Ticks, but they are required to donate blood every so often. At 18, their blood no longer has as much of the teen hormones that the Ticks love so much so they are released (or more likely killed).
Lily and Mel are identical twins living on one of the farms. Mel is austic and has gotten less functional during their time on the farm. They will be turning 18 soon and Lily is trying to figure out a way for them to escape. She tries barrtering for the supplies they will need.
She runs into Carter, a guy she went to school with (and had a huge crush on) in the Before. He recently got to the farm and tries to earn her trust. He catches her trying to sneak off the farm. She's afraid that he's a Collab, but he explains to her that he's on this farm to rescue people, including her. He's teamed up with Sebastian, a vampire who is quite different from the Ticks. Sebastian's not a good guy, but he's not evil either. But he does want to stop Roberto, the vampire who (they think) created the Ticks to begin with. They think that Roberto has an abductura, which is someone who can control the will of others, working for him and that's how the world surrendered to the Ticks so quickly. Carter and Sebastian have been traveling from farm to farm trying to find an abductura of their own that they can use to defeat Roberto.
Lily is skeptical, but her and Mel escape the farm with Carter and Sebastian, along with a couple other former classmates, Joe & McKenna. McKenna is pregnant with Joe's child and he is afraid of what will happen to it after it's born. The escape does not go smoothly. They run into some Ticks, who are attracted to the tracking devices they had implanted in the farm. And the Dean of the farm comes after them. Him and Sebastian were supposed to have a deal to allow him to take them with him, but the Dean has figured out that Sebastian thinks that Lily is an abductura and he wants her for himself. Carter admits to Lily that he thinks that she is one, which she doesn't take well. She doesn't believe that she has this power and is even more upset when Carter explains that he thinks the reason he was into her in school was because of her powers.
They are able to defeat the Collabs that come after them, but the Dean grabs Mel in the confusion. Lily wants to go after them, but they need to regroup and get more gas for their van. They try to find refuge in a church because Ticks aren't supposed to be able to come onto holy ground. But apparently the church isn't iconic enough, but the Ticks attack. They dig out their tracking devices and Joe (presumably) sacrifices himself by taking off with the tracking devices in another car they had found. The rest of the gang heads off to find Mel and the Dean.
They find them and kill the Dean, but are attacked by Ticks. One attacks Lily and it looks like she's going to die when Mel intentionally draws its attention. It attacks and kills her. Lily is able to convince Sebastion to try to turn her into a vampire, which apparently only works 1% of the time. He then insists that they leave because she'll be hungry if it works (which it does). Carter, Lily, and McKenna head to Canada, Lily & Mel's original plan. Lily decides that instead of settling in Canada, that they'll get McKenna there and then Lily with continue on with Carter to Utah, the base of his rebellion against Sebastian.