Hetty Hyssop and her assistant ghosthunters travel to a seaside hotel to investigate the appearance of one of the most dangerous ghosts in the world.

Just a little trip -- Damaged by a ghost -- The first fiery encounter -- Attack in the elevator -- The fourth floor -- Bad, bad, bad -- What now? -- Great excitement -- Ghosts in the afternoon -- A shock in the evening -- Fireworks! -- The idea that saved the day -- Ghosts from the coffeepot.