The Planet of the Dead plunges David Tennant’s Doctor into his ante-penultimate adventure, Planet of the Dead. He’s joined on his adventure by Michelle Ryan as cat-burglar Lady Christina de Souza.

Written by Russell T. Davies and Gareth Roberts this special, the second of five, first aired on 11 April, 2009.

The Doctor finds himself on a bus loaded with travellers, and separated from his TARDIS, when they pass through a spatial anomaly and are pulled to a far distant planet. Trapped there, they have to find a way back to Earth, but not everything is going to go smoothly for the Doctor.

The planet’s inhabitants were destroyed, though the Doctor doesn’t reveal the hows and whys at first, and why the world is covered in what they think is sand. We get introduced to a couple of new alien races, and I quite like the revelation of what is going on, and the threat of it.

There is a nice moment with one of the passengers, Carmen (Ellen Thomas) who has a bit of a psychic ability, and plants some seeds for the finale that is coming up rapidly.

The thing I really like about the episode is the addition of Michelle Ryan, and I love that despite the fact that Christina and the Doctor get along so well, his judgement of her stands. Though he does give her a little bit of assistance with the authorities.

This one is fun, a bit of a romp, and definitely, to me, plays stronger than the previous special.

Davies and Phil Ford pen the next special, The Waters of Mars, which aired nearly seven months later on 15 November, 2009. Whereas Planet of the Dead is just a fun romp – I mean there’s a flying bus! – Water of Mars gets a little darker and scarier.

The Doctor reaches the highest point of his pride and his genius as he arrives at Bowie Base 1 on Mars, where he encounters a fixed point in time, on 21 November, 2059. He knows the names of all the members of the team.

He clashes immediately with the base commander, Adelaide Brooke (Lindsay Duncan), and despite getting along eventually, they are put through a crucible as things start to happen on Bowie Base 1.

There’s something in the water, an intelligent virus. And once the virus is active, the water is unstoppable, and infects, destroys, and drives the story towards an inescapable event.

The Doctor knows everything will turn out badly, but for the first time, as he gets caught up in events, against his better judgement, he works to change events, proving himself the “Time Lord Victorious!”

But his pride takes him too far, even as he tries to stop the unstoppable, Adelaide is determined that things play out the way they were meant to. No matter the cost.

Realising he may have gone too far this time, he is shaken, at story’s end, with an encounter with an Ood which reminds him that his song is coming to an end.

Continuity is rife in the episode, the most important one is the impending arrival of the four knocks. This is something that we think will occur in this episode, but the Doctor refuses to let it. He’s determined not to let go.

But the end is coming, and the four knocks, when they happen, will break hearts.

Next week, it comes to a roaring conclusion as both an old enemy, and a long lost home returns in The End of Time.