Alex and Zach are two 12 year old boys about to enter middle school. They have been friends since Kindergarten but are drifting apart as they reach adolescence. Alex asks Zach to go to the comic book store together on a rainy day before the start of the school year. As the storm subsides the boys splash in puddles on their way home until Zach jumps into a large, electric blue puddle and sinks from sight. Alex jumps in after to help his friend and both find themselves in a new world, Ethuria, ruled by large talking rodents. Bushy leader of the rodents and was raised by rats. Bushy has taken over the city of Ethuria where buildings are made from the gold mined by moles in the distant hills. Alex and Zach need to get back home, but until they can do that they reside with the Puddle Jumpers; a group of kids who Jump between worlds in order to take what they need to survive. Malcolm, the leader, welcomes them into the Puddle Jumper's home, but also chooses who Jumps and who doesn't. Alex and Zach, along with some friends they make along the way, need to work together in their effort to make changes and get back home.