I’m not 100% sure what I was expecting from this episode, but I was mildly surprised by what I found. It was pretty good. The writer, Matthew Graham, had already expressed that he wanted this two-parter to be a lot darker and have more of an impact than his previous outing - the 2012 Olympics based Fear Her.

So, what do we find?

A very beautiful former-monastery on an island, host to some military style living flesh experiments and subject to some solar and electrical disturbances. It’s all a little bit Frankenstein, and you know when someone says not to worry because “it’s just gunge,” you should start to worry because it’s not just gunge.

The Doctor seems different this time out. Once again, he tries to dispatch Rory and Amy to get chips because he wants to be alone, but that doesn’t quite work out. Once upon the island, he seems to be far more in the know than he has been so far this series. In previous episodes, he’s not been afraid to admit that he just doesn’t know the answer.

This time out, he seems to know more than he’s letting on.

There’s a deep story at the heart of this episode - the rights and the morality of cloning. It seems a pretty serious subject for a kid’s show in a pre-7pm TV slot, but I felt it was handled pretty well. So far, anyway.

The duplicate Doctor part was pretty flipping obvious, right from the start. You could see the setup from a mile-off. If there isn’t a “which is the real Doctor” scene next time out, I’ll eat my hat.

For some reason, Rory turns stalker-ish over one of the clones. It seems quite out of character, particularly the bit right before the cliffhanger, where he abandons Amy to run off into imminent danger for a clone he barely knows - particularly when he’d just witnessed her head come through a toilet door seconds after she punched him. Does that sound like Rory? I don’t think so. Perhaps travelling is changing him.

The setting is brilliant, the crumbling and shadowy walls add a lot of atmosphere. Some of that solar-storm CGI, although pretty, was not quite so believable. The moment when the Doctor was climbing the ladder brought back terrible memories of Vampires of Venice.

All in all, I thought this was a good, solid episode. The underlying theme is fascinating, although I do think at points it was trying a bit too hard to ask the questions. The Doctor reiterating over and over that they have their feelings and memories. We get it.

Still, a fascinating opener to a two-part story and I’m keen to see what happens next.