This 7th Doctor storyline has the Doctor arrive on a dystopian human colony where everyone is forced to be happy, all the time, like a whole community of childrens TV presenters. The place is painted in bright, primary colours, muzak fills the air, and if you dont turn that frown upside down then the state absolutely murders you. Killjoys are hunted down by the Happiness Patrol, and executed by a giant robot looking suspiciously like Bertie Bassett so much so, that Bassetts complained to the BBC about it. The robot, called the Kandyman, was a sadistic killer who used deadly sweets to murder people with happiness, but could be stuck to the floor with lemonade. The whole thing was intended to be a satire on Thatcherism, apparently. It would be generous to assume that the audience at the time got the reference. Most of them were likely to be too busy making incredulous faces at each other.