Waters of Mars

I decided to rewatch the 10th Doctor's most dangerous adventure on DVD last night and found it still held up well after five months. 10thy starts off all wide eyed and full of optimism and hope and along the way he gets fearful, regretful and angry at his own impotence before finally becoming arrogant beyond even the Master! When he realises he's gone much too far he realises that his days are numbered, especially when Ood Sigma turns up to sing him a little song.