The final segment of the Key to Comedy seems to lie somewhere on the twin worlds of Ianos and Paulos. Two civilisations locked in an eternal conflict which no one can remember beginning and everyone wants to see end. The Doctor agrees to help the Marshall - the small, cynical and slightly bald leader of Ianos - and journeys to Paulos in search of information. There he finds that a super computer called Mertalis is running the entire war effort single handedly and managing to do so in the manner of Tony Hancock.

But the Doctor discovers to his horror that there is something large and sinister between Ianos and Paulos. The Shadow of Toryism has been lying in wait and, if he can work out who is who, could steal the entire Key to Comedy. If the Shadow were to get his hands on the most powerful weapon in the humorverse, anarchy would reign for all eternity.

"Well, now, erm, um, ah, Doctor isn't it? Yes, right... now... right... um... give that man a coconut if he gives me the... um... key thing."