When Liv moves to London, she meets the mysterious Henry and his group of friends, who pull her into the enthralling world of dream-travel. She and her newfound band of dream-wanderers conduct a ritual to make their biggest dream come true, but it demands the gravest sacrifice.

Sisters September and July share an intense bond, speaking in a secret language and keeping the outside world at a distance. After September is suspended from school, their mother brings them to a remote house on the Irish coast—where July begins to resist her sister’s increasingly sadistic control.