Review of all 4 episodes:
This was the first Doctor Who story to be written by Douglas Adams. The famous writer of The Hitchhiker's Guide to the Galaxy and future Script Editor of Doctor Who is well known for creating quite bonkers but hugely entertaining stories and this is a prime example. There is a crazy, camp, surrealism in this adventure but also some characteristically intelligent dialogue and big science fiction concepts. It makes for a dynamic production.
This is the second part of the 'Key to Time' arc and involves The Doctor, Romana and K-9 searching for the second segment of the Key to Time and encountering a 'pirate planet' Zanak which exploits and destroys other civilisations in order to plunder mineral wealth from other planets.
The explanation for how this is done and for what the backstory is for the different people involved is really fascinating and impressive. The plot is great science fiction but is delivered with Adams' characteristic quirky humour and eccentric style. Tom Baker's equally eccentric personality is perfectly suited and he is a wildly exciting presence throughout. Mary Tamm's Romana also is perfectly suited with her dry humour complimenting the relationship and the witty dialogue.
The Captain is a totally over the top villain but in the comedic style of the story he works as a fun antagonist along with his bullied sidekick Mr. Fibuli and the serious, sinister Nurse. The Mentiads are an interesting addition too.
The effects are acceptable for the day but are not at all impressive and unpolished. The locations and sets are decent though and the ideas themselves are extremely strong.
The humour works really well in combination with the intriguing, big scientific aspects and makes for a joyous serial which zips along providing huge enjoyment.
My ratings: Part 1 - 9/10, Parts 2, 3 & 4 - 9.5/10. Overall - 9.38/10.