The Legacy of Death written by Jonathan Morris and directed by Ken Bentley

What's it about: The Doctor, Romana and K9 have found themselves trapped in a temporal war. On Aoris, the past battles the future - and the future fights back! With both sides of the war now capable of time travel, the conflict is about to enter a deadly stage. As the pieces of history lock into place, there is little the Doctor can do. With more Time Tanks moving into combat, the endgame is approaching. The people of Aoris risk extinction at their own hand. Can even the Doctor save the same planet twice in the same day?

Teeth and Curls: He wont hear of anybody dismantling K.9. He tries to convince that Romana is the expert and that he just follows her about...whilst we know this is not entirely accurate when you watch stories such as Horns of Nimon you have to agree in this season it does start to have a ring of truth about it. There were always moments of drama in season 17, moments when the Doctor's facetiousness stripped away and he brought him the seriousness of the situation. When he calls Emberey a blind, cowardly fool you genuinely believe that the Doctor is dealing with a truly abominable man. Tom Baker always makes these moments count. And when it comes to condemning the other side for acts of murder he is just as succinct. If the Doctor is so against the idea (which he very much is) then it must be very possible to rewrite history and forge a new timeline. Baker is as venomous as Hartnell when delivering the same kind of speech as that in The Aztecs. Why when trying to escape to the public announcements about how a prisoner on the run do they never mention how strikingly handsome he is? Perhaps there is something to the legend of the Doctor if he is to end the war that inspired his reputation.

Noblest of them All: Romana doesn't appreciate being bowed and scraped and fawned at...which is a sign of a strong character.

Standout Performance: Try and get your head around this concept - past and future factions debating the rights and wrongs of fighting against one another. This mind bending idea is made all the more palatable when it brought to life by actors with the skill of Simon Rouse and Tom Chadbon. They really sell the material, there is a palpable feeling of hatred between the two sides of this war. Which is deliciously screwy when you think they are descendants and antecedents of one another.

Sparkling Dialogue: 'We have not harmed a single living soul from your time!' 'Only because you daren't!' We you are talking about your ancestors, those words take on real significance.

'We are the product of your decisions, your short-sightness, your mistakes, your greed!'

'If you want to solve this worlds problems then take responsibility for them! Stop blaming your ancestors and start learning from them!' - a valuable lesson for all of us.

'You can't undo the mistakes of the past, you can only avoid repeating them.'

Great Ideas: Poor old K.9, only he would hang around for over a millennia and continue to follow the instructions of the Doctor. He really is a Time Lord's best friend. The story lends itself to environmental concerns, which feels very Douglas Adams. Things start to get very wibbly wobbly in the second half - the Doctor realises that Emberey's great discovery is what allows them to eventually travel in time, that if it wasn't for him that there would be no war. Rather wonderfully because the story is set in two time zones we can enjoy the Doctor's tinkering in the past and K.9 recounting the events in the future, thus skipping over the boring bits and getting straight to the juicy stuff. K.9 is such a tease, he fails to mention that the Doctor is back in future because getting to that point makes a good story. As I mentioned in The Paradox Planet, the two factions in this war have caused the very thing that they hate about their past and future counterparts. The future faction travelled back in time and kidnapped all the endangered animals and caused them to become extinct. And if it wasn't for the future faction sending their Chronauts back in time to steal the crystals, the people from era 14 would have been able to use them as a power source instead of fossil fuels. What is the greatest weapon you could think of to exploit during a temporal war...the Doctor perhaps? The universe doesn't like self-negating time paradoxes, the Doctor knows that from experience. Perhaps the participants in this war have been gorging themselves on too many Doctor Who stories - they seem to recognise that most of these adventures end by going up in a big bang. If era 24 had never declared war on era 14 they could have negotiated with them to give them the xenox crystals and the animals. It's an old moral (and season seventeen is laden with messages from the hideous blobs not always being threatening, fancy named drugs being bad news and never look a gift bull in the mouth) but stop fighting and start talking is one that the human race needs to learn over and over again. I loved how K.9's 1000 year reputation is dealt with at the last minute, leaving a final cute little twist to bow out on.

Audio Landscape: Circuits shorting out, fizzing and crackling, dripping, impulse setting one, the humming time machine, alarms, chanting, K.9's grinding engine, nose blaster, footsteps on gravel, crackling fire, time jumps, ticking bombs, birds shrieking.

Standout Scene: After Emberey discovered time travel he went missing and presumed dead and the people of the future never quite understood where he went. It turns out he went to the future where he was subsequently killed. There is something very neat about a story that poses a mystery like that that spans a thousand years and answers it with such murderous flair within seconds. That's cracking Jonny Morris plotting for you.

Result: 'Do you want to know who set this planet on a course of self destruction?' 'Yes, I want to know' 'Then look in the mirror!'  More than any other story in his run so far I was extremely impressed with Tom Baker's performance in this story. He's never given a poor performance but there are times when he is characterised as such that it feels more like The Tom Baker Show than Doctor Who. Morris characterises him beautifully in The Legacy of Death, giving him plenty to rail against (and you can hear Baker gnashing those teeth as he takes on both sides in this temporal war) whilst maintaining his sense of humour appropriate to the season. I was genuinely taken aback at how good he was here, which suggests to me that a fair amount of his material previous to this story in the 4DAs has been a beneath him as an actor. Strap yourselves in and prepare yourselves for a complicated ride in The Legacy of Death but never fear, as long as you engage your brain there is a huge amount of reward to be found in the conclusion to this temporal jigsaw puzzle. Don't expect a nice, easy linear ride but do expect some clever twists and plenty of action. Morris is too smart to leave any threads hanging and by the time the story is over he crosses all of his ts and dots all of his is although you might need several listens to get your head around everything. There's a strong message about talking and not fighting and accepting the mistakes from the past and learning from them but it doesn't hammer them home, instead it uses creative ideas to slip them into the narrative. That's very season seventeen. The first half was more entertaining but the second half was more dramatic and for Tom Baker's riveting performance opportunities I felt extremely satisfied with that shift in tone. If only all the 4DAs could be four episodes long: 8/10