Plot: the Doctor finds himself trapped in an intergalactic peepshow, where different life forms are unwittingly caged in small worldlets. He has to save himself and the other prisoners as the peepshow machine disintegrates.

A neat mix of suspense, comedy (particularly the carnival characters), imaginative storyline and the social comment prevalent in the Jon Pertwee years. Perhaps some of the special effects are tacky . . . but this is classic fun.