Well we've had Ronald Colman, Stewart Granger and even Peter Sellars had a go - so it was only fair that Tom Baker got to take his turn at his own version of "The Prisoner of Zenda" in this pretty obvious homage to that famous Anthony Hope story. He and "Romana" (Mary Tamm) arrive on the eponymous planet just as it's weakling prince "Reynart" (Neville Jason) is to be crowned king. Thing is, the evil "Graft Grendel" (Peter Jeffrey) has set his own sights on the throne and by manipulating his android version of a princess who could be the identical twin of "Romana" he hopes to kill quite a few birds with one stone. Luckily, though she falls into the wrong hands, the "Doctor" and "K9" fall into the more loyal ones of "Zadek" (Simon Lack). Now it's straight to the impersonation game with the crown likely to go to robot with the most durable power pack... I enjoyed this. It gives Baker a chance to show off his sword fencing skills, there's a good old fashioned dose of thespian ham from Jeffrey and some of the doubling-up shows off the improving skills of the visual effects department as this four-parter hits the ground running delivering a fun costume adventure in the "Key to Time" series. There's plenty of outdoor photography and Leeds Castle in Kent makes for a perfect backdrop to the mediaeval plot.