Stitched together from a bountiful reservoir of science-fiction allusions, the Waters of Mars triumphed because the most indelible, profound theme was of the Doctor’s dilemma of the clash between his compassion and morality, which was urging him to save the otherwise doomed crew of Bowie Base 1, and the anachronistic edicts of his Time Lord heritage that insisted he abandon them to the whims of fate.
For much of the episode, the Doctor fulfilled the role of an impotent observer, dropping crumbs of detail to the austere Adelaide (Lindsay Duncan) and her crew as they were slowly picked off one by one by the alien entity present in the waters of the red planet. He almost acted as an assessor, appraising their conduct under mortal duress such as when he commended Adelaide for not shooting one of her infected crew. It was only as he strode away from the base back to the Tardis, and heard them being consumed by the entity one by one over the intercom, that his own alien infection, an affinity for the human race usurped his Time Lord ethos.
But all was not well. Tennant superbly conveyed the Doctor’s discomfort at his sacrilege through a grandiose insurrection of his native philosophy; booming grandiosely about how as he was the last of the Time Lords he was able to manipulate time to his own ends as if seeking to deafen his guilt.
He enjoyed the power too much, and upon transporting the three survivors back to London – to Adelaide’s front door no less, just to show off – he tartly demanded gratitude. Acting virtually as his conscience, Adelaide upbraided the Doctor for his actions in bending reality to suit his caprices. Dismissing her protests as the aggravated prattling of an inferior race, he strode back to the Tardis, his lingering humanity as extinct as his own race, until he heard Adelaide’s immolation to straighten the crooked lines of the time stream.
And it was her death that cleverly pricked the Doctor’s conceit, that it was his actions that were responsible for her death and the only sort of atonement he could achieve his through his own death – but even this will be nothing more than a regeneration, and that might not be enough to salve the wound – but as he fell to his knees on witnessing the apparition of Ood Sigma, Tennant’s eyes spoke of the desire that he would ‘die’ at then as the pain, common to his newly liberated humanity, is too much to bear.
The focus of Russell T Davies’ script on the Doctor’s erratic morality excused the simplistic monsters and derivative narrative – they fulfilled their purpose to the letter; they were scary for children and brought with them a dogged menace.
The use of water, a simple everyday object, is more common to Stephen Moffat’s episodes – shadows, statues, clocks – but was used in the Waters of Mars just as effectively. As the infected crew members bled water through the thick concrete base to ambush the fleeing crew below, the normally innocuous sight of a waterfall seeping through the ceiling, trapping a crew member on one side of the room, had the same lethal, visual impact as a relentless buzzsaw.
The idea of an alien entity infecting an isolated colony is, of course, hardly original. John Carpenter’s The Thing, itself a remake, is the most obvious touchstone for this scenario, and the entity’s simplistic psychology of a yearning to invade Earth because of its aquatic abundance was another facile device. But because of the Doctor’s internal conflict, facile was all that was required, or indeed, there was room for.
Even the Doctor’s actions were derivative of previous incarnations of the renegade Time Lord. However, these could be passed off as ingrained traits rather than cynically mining the past for ideas. John Pertwee’s Doctor died as a consequence of the same unchecked hubris exhibited by the contemporary personification, while Patrick Troughton’s Doctor was forced into a regeneration by his superiors for the same kind of interference. Meanwhile, the ghostly figure of Ood Sigma is redolent of the Watcher who presaged Tom Baker’s metamorphosis into Peter Davison.
Such was the vivacity, depth and humanity of Tennant’s portrayal of a conflicted alien that it’s a pity that he’s leaving. But on the other hand, such a detachment from the usually noble and selfless Doctor is only possible during his incorrigible decline, as though he is in a state of decay that can only be remedied by a new face.