The school science fair is fast approaching, and Jacob still hasn't come up with a project. To make matters worse, Mom and Dad have gone away on a trip, and the dreaded Auntie Good-For-You is babysitting Jacob and his siblings. Auntie won't let them do anything which isn't good for them, which means no fun allowed! When Jacob accidentally grows a huge, weird fungus in his closet (with the aid of Auntie's green health shake), he figures that his science project worries are over! If only he can keep it hidden from Auntie and prevent it form eating everything in the house as it grows, and grows, and grows.