After surviving a harrowing case, Alex McKenna just wanted to rest. Unfortunately, his plans are interrupted by the ghost of Seven-year-old Haven, who is lost in an in-between realm.
Despite his great-grandmother's warning, Alex crosses the bridge between the living and the dead, sending him and his girlfriend into the world of the Academy of Souls, a high school for dead teens who are unable to complete their journey.
There, Alex meets Ophelia, Haven's teenage sister, who's been searching for her for more than a century. Together, with a few friends he meets along the way, Alex must cross the treacherous terrain of the Underworld in-between, to save Haven from clutches of the Soul Gatherer and reunite the sisters.