With the grownups all gone, all is peace and harmony in the House of Fun. But not for long! When Stinky finds a mysterious seed in the Attic of Horrors, Icky can't resist planting it. After that, events become unstoppable as things begin to change dramatically. Bryan turns into a girl, a helicopter arrives on the roof, and a toilet is in dire need of emptying. Could this be their perfect world or the start of a nightmare?