It is 1926, and the Doctor and Jo arrive on board the SS Bernice, a small cargo ship peacefully crossing the Indian Ocean. Millions of miles away from Earth, on the planet Inter-Minor, a travelling showman named Vorg and his assistant, Shirna, arrive to entertain the populace. With them is an amazing machine - an intergalactic peepshow called the Scope. As Vorg's show begins, alien worlds and strange creatures are conjured up from the Scope for the watching officials of Inter-Minor... On board the SS Bernice, the journey is suddenly interrupted by the appearance of a Plesiosaur - a dinosaur that died out over 130 million years ago. The Doctor and Jo soon realise that things are not quite what they seem, but can they convince their fellow passengers of the danger they are in? Or will they all be made to suffer in the name of 'entertainment'...?