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.