Alas, a real let down, far and away Mr Platt's worst Doctor Who offering. It starts with two and half minutes of 'sword and sorcery', mixed with a less than original parody of Christianity ("lead us not into perfection, for never and never"), then another two and half minutes of it after the opening theme, followed by lots of descriptions of how blue everything is.
As the story continues, it is dragged down by incessantly portentous dialogue ("Blood feeds on blood!" or "Revenge will taste good"). The alien menace are, don't laugh, "Crocodilians" and it just so happens that crocodiles are what scare the Doctor's companion Lucie more than anything else.
The supporting cast are well below par (Barbara Flynn is great and Sheridan Smith puts in a pretty good show as her altered self but the rest are really flat) and the dialogue is never too far from dumb: "Unless it's a bone brain"; "Lucie, who is in much danger from crocodiles"; "Your prayers balance out the dark of the skull's thoughts".
Nerdy and naff.