Helen A, ruler of colony Terra Alpha, is determined that happiness will prevail. And if any killjoys insist on being mserable, the fun guns of the Happiness Patrol will remove them; or they will vanish into the Kandy Kitchen, where the Kandy Man will deal with them.

When the Doctor and Ace spend a night in the dark streets of Terra Alpha, they have to keep a smile on their faces - or else! - while making contact with the native Pipe People and trying to convince the colonists that they can have too much of a good thing - even sweets and happiness.
 

"HAVE A NICE DEATH!"

The Doctor has heard stories of strange and sinister goings-on on the Earth colony of Terra Alpha. Citizens have disappeared without trace, and strange creatures lurk in the pipes and sewers under the capital city. Believing it is high time someone got to the bottom of the mystery, the Doctor declares to his young companion Ace that tonight will be the night...

He discovers that Terra Alpha is ruled by the tyrannical Helen A, a dictator who requires her subjects to be happy...or die. Her roving death squads - the Happiness Patrol - are empowered to kill on sight anyone displaying signs of sadness, gloom or melancholy.

However, it is not just the sadistic Happiness Patrol that the Doctor and Ace must contend with. Before they can discover the dark secret of Helen A's regime, they must face the fearsome bloodlust of her savage pet, Fifi, and the lethal surprises cooked up by her chief executioner - and confectioner supreme - the Kandy Man...

From the 1997 Video Release

Originally transmitted 2nd - 16th November 1988, this clever and satirical three-part adventure formed part of Doctor Who's 25th Anniversary season.

Written by Graeme Curry
Produced by John Nathan-Turner
Directed by Chris Clough
Kandy Man Illustration: Colin Howard