Well, I absolutely loved this one. It's basically a disaster movie in the mould of a Torchwood episode, only unlike most disaster movies it's a compelling piece of entertainment from start to finish. It's also The Wedding of River Song done right - the people from different times merging (or in this case, falling through rifts in time) actually works much better tonally here than it did in that Doctor Who episode. It explores more of the consequence of this, such as the black death returning to 21st century Cardiff and Roman soldiers slaughtering people, as they are not following the lawful ways of modern life.

Eve Myles is superb in this episode too, and it's great to see the team being tested in Jack's desperation to stop them reopening the rift.

Love the Doctor Who S3 tie-in.