On the planet Terra Alpha, bright fluorescent lights and garish candy-striped colors abound. The population constantly displays happy smiles. There's no sadness on Terra Alpha. Anyone feeling remotely glum disappears. Quickly. Having heard disturbing rumors, the Doctor and Ace arrive to topple the entire regime overnight. But they haven't reckoned upon the varied punitive measures enforced by colony leader Helen There are many delicious ways in which to vanish on Terra Alpha: you can be hunted down by the omnipresent Happiness Patrol or mauled by Helen As ravenous pet Fifi. But those especially unlucky few will find themselves entertained in the sweetie factory manned by Helen As psychotic henchman... The Kandy Man. This time, Happiness will prevail.