Johnny Boo is the best little ghost in the whole world, because he's got Boo Power. This means that he can go "BOO" really loudly. His pet ghost named Squiggle has Squiggle Power, which means that he can fly and do really fast loop-the-loops. Together they have the world's greatest ghost adventures!

When Johnny Boo is busy with another friend, Squiggle tries to make a new friend of his own but instead gets captured by a butterfly-hunting boy.