eader zip right along with a straightforward, breezy plot and two charming, mischievous mice leading the way." -- Bulletin of the Center for Children's Books

Fergus loves being the class pet. When the teacher plans a field trip to a museum, Fergus doesn't want to miss the fun, so he stows away in a backpack and sets off for an adventure. The museum is a little overwhelming -- huge and full of exciting things to see. Luckily, Fergus meets a new friend, Zeke, who knows the ropes, and together they explore everything from moon rocks to butterflies to a giant dinosaur skeleton. But when it's time for the bus to leave, will Fergus make it back to school to take his place as class pet once more?