"It's been 21 days since the hundred landed on Earth. They're the only humans to set foot on the planet in centuries ... or so they thought. Facing an unknown enemy, the hundred struggle to survive the only way they can--together, as secrets are revealed, beliefs are challenged, and relationships are tested"--

After defying the ruthless Enclave, surviving the wasteland, and upending the rigid matriarchy of Sylum, Gaia Stone now faces her biggest challenge ever. She must lead the people of Sylum back to the Enclave and persuade the Protectorat to grant them refuge from the wasteland. In Gaia's absence, the Enclave has grown more cruel, more desperate to experiment on mothers from out side the wall, and now the stakes of cooperating or rebelling have never...