Vito DelSante's "The 13th Floor" gives the gang a bit of history as Freddie visits his detective mentor Adam Stone, currently embroiled in an unusual case of poltergeists. The setting is unusual, but DelSante doesn't provide enough motives for the caster of phantoms. The clues are practically non-existent, and you really can't call this a fairplay mystery or much of a detective story. Where he atones for these deficits is in the kitchen scene, which allows Scooby and Shaggy to provide some genuinely humorous bits, inspired by the show.
Scott Neely does some spectacular work in these pages. There's a cute moment when Adam Stone goes down to Scoob's level to pet him and explain the problem. I've always enjoyed the fact that everybody accepts Scooby as a talking dog and nothing out of the ordinary. Neely provides slapstick moments courtesy of Shaggy and Scooby, and a charming Daphne Blake.