Sign of the Sandman: Séance - Sign of the Sandman Saga, #1.5

One year after the greatest adventure of their young lives, Charlie Galen and his best friend, William "Plug" Harbison, find themselves entangled in a ghostly occurrence that turns their Halloween from a carefree holiday into a spine-tingling evening neither of them will ever forget. Sign of the Sandman: Séance is a novelette sequel to Tom Turner's acclaimed first novel, Sign of the Sandman.