Aliens have mistakenly sent a 'discovery capsule' to Earth and are determined to retrieve it, but before they can, it is found by children on their way to school. Opening it, they pull our ordinary-looking objects--candy, a flashlight, a spray can, etc.--that have strange effects of them. In the mean time, the aliens have placed an invisible wall around the trunk, trapping the children inside and rendering them invisible to the outside world.
