The Ghost of Winter Joy — Michael DiCerto

Strange creatures begin to appear in the normally dull Graysland after Rupert digs up a mysterious bell in his backyard. He sets off with his best pal Squeem to discover the secret of a mysterious haunted mansion, its creepy occupant, and their connection to an all but forgotten old holiday called Winter Joy. Locked in, a prisoner of the mysterious owner of the mansion, Rupert is rescued by Pie O'Sky, who gives him a key that opens a door on a dangerous journey where he will come face-to-face with the Ghost of Winter Joy.