When Emery was 6 years old, an alien spacecraft crashed in her town. It carried a species known as Atrians, and a ferocious battle ensued between the humans and aliens.
In the midst of the war a 6-year-old Atrian boy, named Roman, came across Emery's house. She protected him and fed him - and even became his friend. During this time they forged a deep bond, but Roman was eventually captured by the authorities and believed to have been killed.
10 years later, the Atrians are still on Earth but are interned in a heavily-guarded camp known as the Sector. Now, for the first time, a group of Atrian teens will enroll in high school, with the goal of testing the integration of humans and alien species.
Emery discovers that Roman is actually not dead, and is one of the Atrian students. They rekindle their childhood bond, but their relationship is threatened by tension between the two communities.