The first segment to the Key to Time quest may have been a little underwhelming but thankfully the quality picked up with the next part. The Pirate Planet is a serial by one of Doctor Who's best writers Douglas Adams - yes, the same Douglas Adams who wrote Hitchhiker's Guide To The Galaxy - and represents the very eccentricity that to me defines what Doctor Who as a show is.

I absolutely adore The Pirate Planet and to me it is definitely the high point of the Key to Time saga. The Pirate Planet finds the Doctor (Tom Baker) and Romana (Mary Tamm) arrive on the planet Calufrax to find a population who live in never-ending extreme wealth. They are given wealth by the planet's ruler the pirate captain of the title (Bruce Purchase); the Doctor doesn't trust him and decides to confront him, where he finds out that the captain mines planets for their mineral wealth and keeps their compressed remains as trophies. The Doctor and Romana must stop the Captain from compressing the Earth as well as find the second segment to the Key to Time.

The Pirate Planet is delightfully barmy and that's why it works so well. It's hugely entertaining with its bonkers narrative and larger than life characters reminiscent of those found in Hitchhiker's. It's this madcap nature that perfectly suits Tom Baker's Doctor; this incarnation feels natural in a story like this and it feels like it was actually written with him in mind. There is no way The Pirate Planet could be a William Hartnell or Jon Pertwee serial because it wouldn't work anywhere near as well as it does.

Bruce Purchase is an outstanding choice for the Captain. He gleefully plays to the over the top nature of the serial and is exactly the kind of booming caricature villain this serial needed. Yet whilst he has an almost cartoon-esque quality to his performance, he still appears as more of a credible threat than the Gaff in The Ribos Operation. He still seems like someone who poses a challenge for the Doctor. He never feels like an easy villain for the Doctor and Romana to defeat and most importantly, despite the bombastic nature he still feels real.

A highlight of the serial is the robot parrot Polyphase Avatron. Polyphase Avatron is a pet robot who could easily rival K9 in its awesomeness. Essentially it is like an anti-K9: whilst K9 only fires his laser when necessary, the Polyphase Avatron kills anyone who gets on the wrong side of the captain. It's a brilliant design too by the serial's designer Jon Pusey. It has a nice, almost steampunk to it that nicelyfits Douglas Adams' style. K9 was clearly jealous when he destroyed it. Bad, bad dog.

To me, this is the classic series story that represents Tom Baker at his best. The fourth Doctor in this serial is exactly how most people have come to think of his Doctor: bulging eyes, booming voice, warm eccentricity...all the traits that people refer to the fourth Doctor as having are there. In fact, this serial could have just been called 'Tom Baker' because it pretty much feels like The Tom Baker Show, written by Douglas Adams. That's a very good thing as it shows the writer understood Tom's Doctor personality and how to characterise the fourth Doctor.

What's interesting to note about this story is that whilst working on it, Douglas Adams was also working on the BBC radio version of Hitchhiker's Guide To The Galaxy. It's amazing that this story doesn't suffer from a lack of attention by a Douglas Adams working on a project that was likely more important to him (Doctor Who didn't have the legacy it has today at that time, of course, so it would have just been another job to him). It feels like Douglas Adams put a lot of effort into writing this serial and didn't treat it as just some extra work pay alongside his Hitchhiker's commitments.

Overall, The Pirate Planet is without a doubt the best serial of the Key To Time season. It features a suitably barmy plot by the wonderful Douglas Adams and is the most quintessential Tom Baker story of Tom Baker's time in the TARDIS. The Captain feels like a much more credible threat than The Ribos Operation's 'The Gaff' despite the cartoon-esque nature and is nicely over-played by Bruce Purchase. I also love the robot parrot Polyphase Avatron who is basically like an evil version of K9. Douglas Adams may have been busy writing his Hitchhiker's Guide To The Galaxy BBC radio drama but it doesn't feel like The Pirate Planet was affected by this. It's commendable how he didn't treat Doctor Who as 'just another job' despite it not having the legacy it has gained today but instead wrote the episode to the best of his abilities. This is Douglas Adams at his finest and showcases how he was one of the classic series' best writers