The Green Death is everything Doctor Who should be.

The Doctor is on excellent form, working with others - including a great working relationship with Professor Jones, when it would be so easy to write them as competitors. His relationship with the Brigadier has so much depth to it now, compared with Spearhead From Space, and really shows the value in having long-running characters. Their points of view might not be exactly aligned, but they listen to each other and show proper respect.

Jo Grant really is at the centre of the story, and there's no way you could replace her with any other companion, the way you could with so many lesser stories. Her interactions with everyone - as superbly played by Katy Manning - are supremely realistic. Things might seem a bit sudden on first watching, but isn't that a characteristic of Jo herself? Right from her first scene you could see the makings of it. And that ending...

Another great quality is how the story doesn't take itself too seriously. There is some horror with what's happening to affected characters - what great special effects! - but the story knows when to have fun too. Pertwee gets to do some great dressing-up. There some wonderful moments where the editing creates jokes in itself. Even the villain is inspired, and a true step up from similar ones seen previously.

Yes, some of the special effects are a bit rubbish - my only memory from watching a repeat of this when I was a young kid was of the really bad green-screen stuff - but when you're swept up in the story that only adds to the charm. And let's face it, it wouldn't be Classic Who with a bit of naff as well.

I'm not sure I would recommend this as a must-watch for people new to Doctor Who, as the real joy is in the relationship between the Doctor, the Brig and Jo, but my goodness it is an absolute delight.

We have the Season 10 finale The Green Death, the end of Pertwee’s fourth season and Jo’s final story. It’s your usual UNIT story setup where some new company has set up what appears to be a clean energy enterprise, but under the surface lies something sinister. But on this occasion it’s nothing alien, it’s just humans who’ve gone too far with their waste disposal, pumping all waste into the mines, creating a toxic slime that kills anyone who touches it, except a nest of maggots who begin to grow to alarming size, their bites carry to toxins from the slime and it’s only a matter of time before they grow into giant flies. Overseeing the whole operation is a man-made supercomputer called BOSS, who’s basically Hal 900 but with the sanity of Holly from Red Dwarf.

For Modern Who fans, think Arachnids in the UK from the Whittaker era, but longer and better. Though admittedly The Green Death has had its naysayers over the years for valid reasons. A lot of the effects, including the blue screening and the giant fly are in the worse half of Classic Who’s terrible effects, the story is a tad too long with some sequences that feel like they’re just trying to kill time, Jo leaving falls into the category of a companion falling in love and wanting to marry someone they only just met at the start of the story, and really at this point the whole UNIT formula was becoming a bit tired and played out.

All these are very valid, but they’re also countered by some of Classic Who’s best practical effects with the giant maggots, one of my favourite one-off villains in the BOSS who has one of the best voices of any Doctor Who villains, it’s a refreshing and bold take for the threat this time to be something that isn’t alien for once. We even get in rare form for Classic Who foreshadowing of the Doctor’s regeneration the following year, we get a sequence where he travels to Metabilus III to retrieve one of their crystals, something that seems so inconsequential but goes on to have huge ramifications later on. Jo’s decision to marry Cliff after only a few days knowing him (and he was unconscious for a portion of it) is far-fetched when it would’ve been fine if she’d just stay to begin her relationship. But the romance is better developed and more believable than how it was handled for other companions like Susan, Leela and especially Peri! And it does lead into one of my favourite endings and companion departures. After beginning their relationship on bad terms with the Doctor being frustrated with Jo’s clumsiness, the two formed one of the strongest bonds between a Doctor and companion, one of the closest in Classic Who to being akin to a romance, Jo even says that Cliff reminds her of a younger version of the Doctor, which is as close a confirmation as we can get. When she agrees to marry Cliff and leave with him to travel to the amazon, the Doctor shares some final heartfelt words with her and gifts her the Metabilus crystal, and then whilst everyone begins to celebrate, dance and sing, he stands away from the crowd, finishes his glass of champagne, then quietly leaves and drives off into the night. No tears, no speeches, no wailing music, just very simple but powerfully effective and above all subtle! Something Russel T. Davies could learn a thing or two from!

This story was absolutely great. All six episodes were quick, and a very good watch. Pertwee was absolutely spectacular, with the Brigadier back to his blowing-up days. I'm somewhat unsurprised, but the main drawing point for this story was Jo's departure. It definitely tugged at my heartstrings, but I didn't like how the Doctor didn't at least say goodbye. It makes sense, though, since we've never seen the 3rd Doctor actually say goodbye. Liz left off-screen, and Sarah stuck around until after he regenerated. Canon be damned, I like the idea that 3 turned up at Jo's wedding.

Oh I HATE JOS LOVE INTEREST

We've not seen a story with this sense of scale since The Daemons, it did not surprise me when I found out that The Green Death was also penned by Robert Sloman who can now add a second excellent story to his name (lets not talk about The Time Monster).

Jo's ending is superbly handled, in an unprecedented and heartwarming exit. After years of unbelievable love stories - they finally achieved it here. As usual the relationship developed very quickly, but a lot more work was put into making it as believable as possible. She was ready to leave The Doctor before he even shoots off to Meteblis Three and was already gushing over Professor Cliff Jones before meeting him, but this relationship was marvelously built up over six episodes - he felt like a fitting substitute for The Doctor. It feels like another milestone for the show. Of course, the fact the actor was actually in a relationship with Katy Manning must have helped sell their onscreen romance.

The direction and editing was better than ever in this adventure - The Doctor and Jo say goodbye, he exits, she stays at the party. The two scenes are intercut with each other - Jo with her new fiance and friends, The Doctor - on his own, driving away. It was very sensitively handled, brave and emotional (though not over the top). Similar techniques are employed at the beginning of The Green Death when the gorgeous and mind bending Metebelis Three scenes are cut between the more ordinary but intriguing goings on Earth. The Metebelis Three scenes look like genuinely expensive film sequences, the giant bird, trademark Third Doctor tentacle and mysterious blue planet had a very memorable effect. It is rare to see this much pace and action in Doctor Who - but it was most welcome.

The maggots were an amazing concept for a menacing force - some of the ways of displaying giant maggots were more convincing than others, but it was a fantastic effort all round. The animatronic maggots on location in the slag heaps looked particularly good.

This was a story full to the brim with great characters. The return of UNIT was wonderful, it's brilliant to have that team back again. It was a superb story for Mike Yates who is interestingly given something quite different to do. UNIT are served better in this story through not having been in the show every week. The UNIT crew act as an interesting social middle ground between the lefties at the Nut Hutch and the seemingly malicious and cruel businessmen covering up malpractice at the plant. The writing that went into crafting these characters not only helped sell the social themes of the story - but could genuinely instill opinions in children that would last a lifetime.

I wasn't sure about Jo Grant when she first entered The Doctor's life. But her relationship with the Third Doctor has been absolutely marvelous. We've seen Jo grow as a character over three seasons and instill a sparky energy into the show. This was a fitting final episode for such an important character. I'm relieved that her era ended on a high. Jo Grant will be missed.