The year their mother dies, Lucas and Casey are sent to their Great Aunt June in Maine to spend the summer—a summer where they pass the days playing with neighbors Aria and Jordan, who help ease the loss. Seven years later, the siblings find themselves back in Maine under much different circumstances—Lucas has been outed as gay at school, and Casey has convinced their angry father to let Lucas spend the summer away. Lucas seeks out his old friends, but the entire town, including Jordan, is strangely adamant that Aria never existed in the first place. When they unearth a strange box in the attic of a burned and abandoned house, its inexplicable contents leave them with more questions than answers. Lucas, Casey, and Jordan set out to uncover the truth of what happened to Aria, and in the process discover things about themselves and the peaceful seaside town they never could have imagined.