OMVGs*, that was scary! Actually, no wait, it was more like mild peril and seriously disturbing, more so in the last five minutes than the entire hour-long episode in which we see a totally different version of the Doctor, one that’s much more arrogant and power mad. Scary stuff.

So, the Doctor finds himself on Mars in 2059. He’s traveling, sans companion this time, and just wants to have some fun, apparently. Except he finds himself on Bowie Base One, the first expedition to the Red Planet which ended in tragedy though no one on Earth ever found out why. The base was destroyed on 21st November 2059 when Captain Adelaide Brooke detonated the facility’s nuclear device. Guess what day the Doctor has landed?

As with other stellar episodes which include Blink and the Midnight, The Waters of Mars is so deeply disturbing because the alien of the week is not an alien but a thing, an element: water. Or, as the Doctor christens it, ‘The Flood’.  Cue an hour of frantic running around, the culling of minor cast members and a very different, darker Doctor.

Using water as an evil force is quite ingenious as well as simple and unsettling. Water is one of the primal forces, it can be dammed temporarily but not stopped. As humans, we also need it to survive and the idea of something so important to life suddenly becoming a virus-like thing which mutates and twists the poor souls who are infected. Now that’s creepy. Especially considering no proper explanation is given, yes there as allusions to previous serials and possible origins for The Flood but we never find out what they are, only that they want Earth. That’s really all you need to know though and this lack of info does heighten the story.

The episode itself is well structured and minor characters survive, who you might not expect to do so but many die needless and surprisingly emotive deaths. Well they are infected but they may as well have died, for all intents and purposes. The idea of setting the story on Mars is brilliant as, despite being our nearest neighbour, there’s something deeply unsettling about the planet, as if it might be haunted by the embers of a long dead race. In this case its once that has been sleeping beneath the ice that allows the team of Bowie Base One (get it?) to survive on the Red Planet

But the really disturbing bit is a lot closer to home. Through the course of the episode, the Doctor goes from ‘I really need to leave’ to ‘screw it, let’s save some people’. He goes on some kind of twisted power trip that almost echoes madness. As if something has changed him for the worse, turning him from his path to a much darker road. Yet as the details of the changed timeline flash, he has an epiphany – in the form of everybody’s favourite Ood, Sigma – and realises he is not a god but a Time Lord – and they are not the same thing. Suddenly faced with the shadow of his own mortality and the ringing of the Cloister Bell, we have six weeks to find out how far the Doctor will go to confront his own death.

The End of Time is coming … we just have to wait for Christmas.

*Oh my various gods.