A group of disabled people, referred to as UnPerfects or U.P.s, are living in their newly established society called Southing on the planet Hollow. Back on Earth, the UnPerfects were gathered and killed in camps before the Perfects, or non-disabled people, devised a plan to send them to Hollow to live in isolation. They were sent with a group of soldiers, but, once there, the soldiers were overthrown and killed, and the UnPerfects have since established a close community. When West is notified of a new Arrival, a disabled infant sent to Southing from Earth, she goes to retrieve the baby, and finds a note wrapped within the blankets. The note is addressed to the General, but, though the people on Earth are unaware, the General and all the soldiers have been killed. West approaches her friend and reveals the contents of the note: more soldiers are coming in the next six months. When they arrive, West knows their whole community will be killed. West gathers the other Earlies, the U.P.s who arrived at Southing as adults, to try to make a plan. Though some want to protect the Arrivals from the truth, they ultimately decide to tell them about their time on Earth, at least those who are old enough to understand. Finally, a group decides to leave Southing and journey across Hollow and into hiding. They know the Perfects will not try to look for them. They will just assume they are dead. One of the group's members, an Arrival named Ona, leaves a note for those staying at Southing and any new Arrivals who may be sent there. Ona explains that their group hopes to return to Southing when they believe it is safe, and she hopes the others will still be alive to welcome them home. In the letter, Ona also tells them about Southing's history and the Earlies who established the city, hoping their lives will never be forgotten.