The books opens with Cassie, Sam, Ben/Zombie, Dumbo, Poundcake, Ringer and Teacup all holed up in a hotel that they escaped to after the explosion at the training camp. The plan is to head for some nearby caverns but Cassie wants to wait for Evan to arrive, as he promised he would.  The others think he died in the explosion, and Ringer heads out to scope out the caverns.  Teacup sneaks out to follow her, and Ringer accidentally shoots her. Back at the hotel, arguing continues.  Ben and Cassie set out to explore the hotel further, and Cassie runs into an intruder.

Part II tells Evan’s story.  After the explosion, he was rescued by a woman from his past, named Grace.  He and Grace met as teenagers, and Grace is very much one of the Others who does not like humans at all. Evan is badly burned and has broken his ankle, but he is determined to find Cassie.  He escapes from Grace, thinking he’s killed her, but quickly learns he was mistaken.  He finds his way to the hotel, where Cassie shoots him in the leg, not realizing who it is.

Debates continue over what to do, now that Evan has arrived but is injured badly.  A young girl appears out of nowhere; Sam recognizes her as one of the kids from the school bus that took him to the training camp.  With Evan’s help, the gang learns that the Others are implanting bombs into children’s throats, and these bombs are activated by CO2, so when a rescuer tries to remove it and breathes on it, it explodes.  Cassie and Evan manage to remove the device.

Grace shows up and she is sorely pissed.  Everyone manages to escape the hotel, except for Evan and Poundcake.  Poundcake, injured, gets a hold of the explosive device and sets it off.

Meanwhile, Ringer has allowed herself and Teacup to be captured so Teacup can get medical attention.  She finds herself in the presence of Colonel Vosch, who refuses to tell her where Teacup is, or if she’s alive.  This drags on for a bit with lots of back-and-forth.  In the meantime, Ringer is being cared for by a nurse named Razor.  She befriends him and the two of them begin communicating by a complex code that is disguised as a game Razor invented. For reasons that are unclear, a procedure is performed on Ringer that inserts 40,000 micro-robots in her, known as the 12th System.  Over time, she heals, and she and Razor devise an escape plan.  During the escape, we learn that the 12th System has endowed Ringer with superhuman strength, speed and healing ability, just like the Others.  They escape, but Ringer learns the whole thing was just a test.  Then there’s some really weird shit with Ringer having a theorey how there are no Others at all (I think?) and I’m really not sure what happened there, but Ringer thinks Vosch is using her to find Evan.  Evan is somehow off the grid from the rest of the Others, or whatever.  

Back at the hotel, we learn that Evan survived after all.