I may risk sounding overdramatic, but my most recent viewing The Waters of Mars shook me to my core. The first half hour has little shards of frothy fun poking through the mix but the last half hour absolutely crushed me as the inevitable fate of Adelaide Brooke's outpost team becomes clearer and clearer. It is their hope and their ever diminishing chances of saving themselves, that kills you. I don't know if Doctor Who has ever been darker. I don't know if you'd really want Doctor Who to ever be darker than this. For this piece of television though they get the balance right. It is right that in and amongst the run-arounds at Easter and Christmas that you get this cathartic, tragic, horrible, emotive episode.

The links back to The Fires of Pompeii are quite rightly called out in the episode itself but there is a key difference for the audience. We don't mourn the people of Pompeii with the same potency of the people of Bowie Base One. Not because they are not as human - they are in fact real historical figures who we should be able to empathise better with than entirely fictional characters - but because the people of Pompeii are set in the past, their deaths feel natural, inevitable and okay. The fact that The Doctor is able to save one Pompeiian family is cause of celebration. The fact that The Doctor is only able to save two members of Bowie Base One is a tragedy because Doctor Who usually makes the future a safe place where the right thing will always happen in the end. As one unlikely piece of hope is dangled after another you are left with your heart in your stomach - until the terrible conclusion finally arrives.

The only criticisms you could lay at the door of this story are the intrusive newspaper cutting flashbacks which seem unnecessary to me, especially more than one or two of them. It is a weird and unsatisfying visual to put onscreen that many times. Though, I sympathise for Phil Ford & Russell T Davies who do not have a companion for The Doctor to communicate some much needed "history" to regarding the events of 21 November 2059.

How refreshing though to have a story with no companion. I know they presented Lyndsey Duncan's Adelaide Brooke as a companion ahead of broadcast but what she actually is, is one of the best lead guest characters the show has ever seen. The lack of her being a "companion" is one of the key things that makes this story so gobsmacking. So unsafe. So uncertain. Anything could happen and it does.

Clearly the most shocking thing they did with her character was to have her kill herself at the end. It may have been with a zappy sci-fi gun, but its a suicide in a family TV show. She felt that she should have died on that base. She should have gone down with her crew. So The Doctor "mastering time" to keep her alive is not enough. She did not think the outcome was right, or would lead to a better future for humanity, so she righted it herself. Tea-time brutally for tots indeed. What makes this even more shocking is that the show was set in 2059 and someone of Adelaide's age would have been born in the same year as a 10-year-old watching the show in 2009. Ford and Davies are saying to the target audience: "THIS IS YOUR FUTURE". Never before has the show dared to stray into this territory and perhaps it will never do again. "Gadget gadget" is not going to soften that blow.