"Kaz, Claire, and Little John are off to Seattle, where a new mystery awaits. The city library is planning a Halloween party, but a series of strange ghostly happenings has scared away all the kids. Now Claire and the ghosts must go underneath the city to find out who is trying to stop the party--and why"--Page [4] of cover.

The Underground Ghosts #10: A Super Special 2017, Grosset & Dunlap

ISBN-13: 9780515157116

Trade paperback