When Geronimo receives an urgent message from Professor Sandsnout just before Halloween, he rushes over to the Egyptian Mouseum in New Mouse City and discovers real live mummies.

While on a field trip to New York's Museum of Natural History, Joe, Sam, and Fred travel one hundred years into the future, where they encounter robots, anti-gravity disks, and their own grandchildren.

During a class field trip to a Pilgrim village recreation, Katie finds herself replacing an actor playing a Pilgrim and, later, when her family goes to New York City, she becomes a clown in the Thanksgiving Day parade.

Wishbone and his friends try to find out who is threatening to destroy the exhibit of a newly-discovered dinosaur at the Oakdale College Museum of Natural History.

Heloise lives with her strict and forbidding godmother in an isolated cottage where the emphasis is on doing one's duty and avoiding all things which could be considered a waste of time. Next door is a sinister museum dedicated to the memory of Mary Child. Visitors enter the museum with a smile, but depart with fear in their eyes. Heloise has never been in the museum.

Billy Broccoli is used to getting expert advice -- wanted or not -- from the ghost with the most, Hoover Porterhouse! The Hoove has smooth moves and a silver tongue...and he isn't shy about sharing his words of wisdom! But when a night at the useum finds Hoover face-to-face with the ghost of a powerful Chumash Indian princess, his brain turns into mashed potatoes. Now the tables are turned and it's up to Billy to help Hoover find the words he needs...