Chelsea's stepmom invented a gun that can change the size of anything it zaps. When she entrusts Chelsea to use it for a Halloween party, the fun doesn't end at shrinking down the guests and playing in a miniature dance house. Chelsea learns that the size gun is a wonderful addition to the bedroom, and the size-themed party starts to go in directions she never thought.
Being big is as much fun as being small! But what will her stepmom think when she finds out how the gun was used?