As she grows close to the spirits in the ghost world, a driven Maddie begins to unravel the events surrounding her death, only to discover someone other than Xavier may have been involved.

When the search for Maddie's killer puts Simon in real jeopardy and exposes Maddie's connection to the living world, Maddie must navigate Split River High's spooky spectral underbelly - first alone, and then with the help of her fellow ghosts.