The world had already begun to change, in ways Carl had no idea were possible, when the voices began speaking to him on the night of his sixth birthday. When Carl’s mom contacted Dr. Emerson Sharod at the Freedom Institute, she had no idea that the time she cherished with her son would end.
Twenty-two years later, the voices urge Carl to leave the Freedom Institute after a man is slain under suspicious circumstances. He doesn’t question them and naively crosses the threshold into the city of Montford, where he knows no one. A few help him, risking their safety, so he can escape the walled city and begin his trek to find his mom in Saratin.
The world outside the walls is stranger than the city with unknown dangers at every step, though not everyone is a foe. Along the way, he meets many who help him and share stories about what caused the changes in the world. When he reaches Base 40, he comes face to face with Astrid, who rescued him from freaks on the first day of his travels. He is worried that she will tell the baser leader, Corporal Phelps, that he’s the escapee from the Freedom Institute, but she does not.
After an uncomfortable meal with Corporal Phelps, Carl shares his story with Astrid. She agrees to take him to Saratin. Reaching the tent city outside the walls of Saratin, they search for refuge and are taken in by Kenneth who is partially responsible for the chaos in the world. The safe place is quickly infiltrated by Corporal Phelps, and they are taken back to Base 40 where Carl witnesses the Corporal torturing Astrid. In a moment of anguish, Carl remembers something he was told and puts together a plan to save Astrid and himself, and, unknowingly, the world.