It is 177 years in the future. The world economy is unified through the International Trade Organization. Worldwide security is provided by the Warrior caste of Lacedaemon, Inc., which is patterned after ancient Sparta. Cillian and his twin Pridbor are born into the Warrior caste as the property of Lacedaemon. They are an experiment of the Threshold project, the Boost - an attempt to produce a more lethal warrior. However, a technical error at birth separates the twins. Cillian becomes Bartlett Starling, a member of the Worker caste, the lowest caste in the industrial zone of The Citadel, a ruthless arm of Lacedaemon, Inc. that discards imperfect children to the Ditch to die. However, unbeknownst to Lacedaemon, Inc. not all of the discards have died in the Ditch, but if The Citadel discovers that they have lived, they will be killed. Bartlett discovers them. Bartlett has one chance to return to the Warrior caste, The Challenge. If he fails, he dies or returns to the industrial zone. In his battle to find the right path, he must decide whether to kill or be killed, who to trust and not trust, and if the Discards of the Citadel should be saved. Will he win The Challenge and turn them in or discover his humanity and keep them a secret?
