A sudden disease kills over 20% of the children throughout the world, leaving the survivors with unusual abilities. As a result, the governments of the world place the survivors in a “rehabilitation camp”, where they attempt to cure the children of their disease, distinguishing them into classes based on their abilities.
Ruby Daly celebrates her tenth birthday with her family, where her father gives her a keychain. Seeing her parents’ concern about the disease, Ruby tries to comfort her mother in the night, touching her hand, and inadvertently erasing all her memories with Ruby. In the morning, her mother locks Ruby in the garage; having no recollection of her, she sends Ruby to an internment camp, where Ruby is determined to be an Orange, one of the most dangerous classes where they have the abilities to control other people’s minds and memories. Ruby uses her abilities to convince her supervisor that she is a Green, the least dangerous ones with extremely high intelligence.
Six years later, Ruby is found out to be an Orange following a test using a frequency that is only detectable by Oranges. Cate Begbie, a doctor, whose real name is Cate Connor, reveals herself to be part of the Children’s League, an organization that uses the survivors as soldiers, and helps Ruby in her escape from the camp. The two make their way to a gas station, where Cate provides Ruby with a pendant that can be activated into a tracker, in the case she is in danger. Cate introduces her to an associate of the League; a suspicious Ruby makes her escape from the station with a little girl named Suzume, a Gold who has the ability to control electricity. Suzume, shortened to Zu, introduces Ruby to her friends, Liam, a Blue who has telekinetic abilities, and Charles, known as Chubs, a Green, who agreed to let Ruby join them as they try to make their way to a safe haven, led by another Orange “Slip Kid”.
