Finally we have reached the final segment of the Key to Time - found in the Key To Time season finale The Armageddon Factor. An interesting note to make about The Armaggedon Factor is that Part One was the five hundredth episode of the show. Unlike The Stones of Blood, The Armageddon Factor is a much more memorable milestone story too (although it does have the advantage of being the finale).

The Armageddon Factor sees the Doctor (Tom Baker) and Romana (Mary Tamm) arrive on Atrios: a planet that's at war with neighbouring planet Zeos. They are discovered by the Marshal (John Woodvine), Atrios's commander in the war and decide to flee back to the TARDIS. However they find the TARDIS has gone, trapping them on the planet. The Marshal persuades the Doctor to help Atrios in the war. During the story, they meet Princess Astra (played by future Romana Lalla Ward) who is the last Royal Family member of the sixth royal house of Atrios. Meanwhile, one of the Black Guardian's agents - The Shadow (William Squire) - is also looking for the last segment of the Key to Time.

The story feels suitably epic, like a new series finale of the Russell T Davies era. This is the Bad Wolf/Parting of the Ways of the classic series: huge fun to watch, with a certain comic-book feel to the events of the story. I think it's impossible not to be gripped by this story; personally I never lost interest once and I think this would be a good classic series serial to introduce to new fans of Doctor Who. It doesn't matter if they haven't seen previous Key to Time serials: you don't need to know the actual events of the past stories, only that the Doctor and Romana have currently acquired five of the Key to Time segments and the Doctor was sent on a mission by the White Guardian to find them before the Black Guardian does. All of this could probably be picked up by only watching The Armaggedon Factor anyway.

I imagine this serial was one that didn't go down well with Mary Whitehouse as there are a number of dark themes in this story such as nuclear war and death threats. Perhaps the darkest of all however is the real identity of Princess Astra, who is revealed to be the last segment of the Key to Time. Her existence comes to an end when Romana uses her tracer to return her to her true form, meaning that whilst she didn't actually exist she believed she did and still had a life.

It's nice when the show explores such dark themes as it helps add a hint of realism without overstepping the mark with the dark/gritty rubbish that's plaguing Hollywood. Not everything has to be cosy and sometimes it is better for Doctor Who to unsettle its audience.

One of the best elements of this serial is evil K9. K9 works well as an extra threat for the Doctor and Romana when he's being controlled via a device by The Shadow. It's disturbing to see one of the Doctor's companions turn against the Doctor and Romana and it helps to showcase the Shadow as one of the most serious threats for the Doctor to face. This isn't any old villain, he knows exactly what he's doing and how to get it. It also neatly ties in with the sense of loyalty people have with their dogs: the idea that their dogs would never betray them. So what happens when they do? If you can't even trust your pet dog, then who do you trust? Turning K9 temporarily evil was definitely a good idea.

Of course, you can't do a review of The Armageddon Factor without mentioning Drax. Drax's introduction isn't very strong (he literally appears out of nowhere) but he is one of the show's strongest guest characters. He's a renegade Time Lord who was in the same class as the Doctor at the Prydonian Academy. He works as a galactic maintenance man and a death threat from The Shadow forced him to work on the planet Zeos's giant computer Mentalis. Barry Jackson is a revelation as Drax and it's a shame he was never brought back as a recurring character in the television series. Thankfully Big Finish has since brought Drax back with the fourth Doctor audio The Trouble With Drax, albeit not with Barry Jackson (who sadly passed away in 2013) but with Ray Brooks voicing the character.

One thing I would say about The Armaggedon Factor is the conclusion is a little weak. It feels a bit rushed and a little like a slap in the face to what was set up in the first serial (rather than giving the Key to Time to the White Guardian, theydecide to scatter it across time and space, so the Key to Time segments end up exactly as they were at the beginning of the serial anyway). It almost feels like the Doctor didn't properly think it through, because if the segments are once again scatted across time and space, what happens if they fall in the wrong hands - IE the Black Guardian?

I haven't listened to Big Finish's Key 2 Time yet so maybe Big Finish have explored what happened with the segments since the Key to Time's conclusion but it certainly doesn't feel like a strong end to the final Key To Time serial.

Overall, The Armageddon Factor is a spectacular end to the Key to Time arc. It's a story that would make a nice introduction to new fans of the show and features some cool ideas such as an evil K9 and the Doctor's classmate Drax. There are some dark themes but they aren't treated in a dark/gritty way as with the trend in Hollywood movies but help to unsettle the audience. My only real criticism is that the conclusion is a bit disappointing; other than that, The Armageddon Factor is definitely worth your time.

A fine story, perfectly enjoyable but nothing special.

I think the thing I enjoyed the most about this serial was how often it made me think of a much better Star Trek episode that pulled off the concept of fighting an endless war against a secret machine much better in a third of the time.

I've been waiting for a sentient segment of the key since the very beginning, and I was a little disappointed by how little they seemed to do with the concept. She sacrifices herself willingly and the Doctor and Romana are barely forced to grapple with the implications before everything resets.

The shrinking was clearly added to pad the runtime but I enjoyed Drax and learning a bit more about the Doctor's history.

The story itself has a lot of potential and several interesting concepts, but there was no need to have 6 parts, it would be much better if it were only 4, unnecessarily long.

This is part of a series of reviews of Doctor Who in chronological timeline order.

Previous Story: The Power of Kroll

That was, interesting, to say the least. I'm noticing that a lot of these 6-part finales just feel all over the place and that is something this story suffers from quite heavily. It's still a fun ending to the Key to Time but I can see why it's not the most popular story. I genuinely think by this point, there is no place for 6-part stories anymore, this could have easily been done in 4.

It's got a good setting, in the middle of a war. Unfortunately, compared to every other story of this season, the world doesn't feel fleshed out whatsoever, despite being 6 parts long, this is the least worldbuilding in this season. The first three parts to this story are very dull and nothing much is progressed in them. It starts to pick up in pace by part 4 but then we just get a new kind of dull in the form of running back and forth while nothing worthwhile happens. I did enjoy the character of Drax, even if I thought he was a strange addition towards the end of an already very cluttered story. When he miniaturises the Doctor, it feels so forced, like it only happened to pad out the story a bit longer.

I think the ending is a bit silly, what with scattering the pieces back so it can be done all over again later. The acting is all right from the main cast, but all of the supporting cast, bar Barry Jackson's Drax are really dull and uninteresting, even Lalla Ward as Princess Astra is dull. It's unfortunate that one of my favourite seasons so far has to end in such a mediocre way. Still though, it didn't bore me, which is something I find really important in Doctor Who.

Next Story: The Auntie Matter

Season review: 8/10

I really liked this season on the whole, I think it was full of rich storytelling and vibrant settings, it had a cosy format, similar to that of the overarching series arcs of New Who and I enjoyed the pairing of the Doctor and Romana I. It would honestly be a 10 if it weren't for The Power of Kroll and The Armageddon Factor being upsettingly mediocre.

The last Dave Martin script! Feels like a milestone given that with Bob Baker he made a whopping 8 serials - few writers on Who have had more screen time. Perhaps apt then that this really *feels* like a series finale in the modern sense, wrapping up our journey with the key to time. Their first script, The Claws of Axos, still stands as by far their best unfortunately, but this story is one of their better ones. Merac’s psychedelic experience at the hand of Lalla Ward’s character nicely calls back to Claws. Baker and Martin often have those cool, very visual, druggy looking scenes.

An interesting revelation comes in part 3, when the twin planet that the army has been locked in a war with is in fact home to only one entity - an emotionless robot that has been running the whole show on behalf of a shadowy master. There are some neat concepts at the heart of the story but sometimes in the process of getting to those points you have to sit through some fairly workmanlike, serviceable but not particularly exciting plotting.

The time loops in this story are a great idea - but you spend probably 2 minutes of running time watching the same loops again and again. That countdown gets dull. Drax, the time lord who spent many years in Brixton reveals Douglas Adams as the script editor - it’s a fantastic idea but I do wish his character had been bedded in a bit better with more time on screen.

I love that K-9 gets his hero moment with Drax and The Doctor jumping out of him at the end in their miniaturised form. Lovely to see Lalla Ward with K-9 - pointing towards an exciting new era.

I’m not sure the whole “key to time” thing adds up to much in the end. It was disbanded as quickly as it's pulled together but was a good mcguffin to tie the series together. About as meaningful as “bad wolf” anyway. This series was not quite as good as Tom’s first three but was a huge step up from season 15.