Robbie finds Stephanie's diary and writes mean things in it about her friends. Stephanie doesn't understand why no one likes her all the sudden. Sportacus appears to help Stephanie get her friends back.
To help clean his room, Pixel builds a machine that makes things disappear. But it really only makes things invisible. Robbie soon steals the zapper and causes Sportacus to vanish. Can Pixel stop Robbie before all LazyTown vanishes?