Flying through the mist and looking for shelter, Rudi and Trudi discover a small cave and decide to go in. Surprisingly, the cave starts to move and Rudi and Trudi find themselves heading down a long tunnel. What they don't know is that they have fallen inside a giant's brain. Huge filing cabinets line the walls of the brain, which are full of memories, hopes and all manner of other thoughts. Suddenly they hear a ghostly voice explaining all. The "voices" are locked up behind a barred metal door. Rudi all too hastily frees them. They turn out to be angry bad tempered thoughts, now running wild inside the giant’s head.
Suddenly the giant wakes up and feeling very cranky, vents his anger across the land. In an attempt to solve the situation, the two friends are sneezed out of the giants nose and witness the destruction. They decide that they must do something so Rudi and Trudi climb back inside the giant's head. Once inside, Rudi comes up with a plan to cheer the angry thoughts up. By tricking the thoughts in to a bit of redecorating, their brighter surroundings cheer them up and in turn the giant returns to his more gentle self. The giant then helps to rebuild the damage done earlier and peace is restored.