With this episode, the Tenth Doctor gets his reign underway proper, after spending most of the last episode in his pyjamas. No more of that - he’s got a suit, he’s got a TARDIS, and he’s got places to be.

New New Earth for a New New Doctor. The first few scenes really cement the relationship between Rose and the Doctor. He’s brand new, but she’s willing to stick with him. In fact, she’s already showing signs of liking this Doctor more than the previous one. They’re like a new couple on a date, picnicking on the applegrass. Mmm, applegrass.

It’s not all meadows and sunshine, though. For this episode, we’re heading straight to a hospital, where new technology is saving the lives of people who probably shouldn’t still be alive given the wide range of scary-sounding diseases.

Although the Doctor is dissatisfied with the lack of a gift shop (“Not a big one, just a shop. So people can shop.”), he can’t fail to be impressed at the disinfecting lifts. I loved that bit. It reminded me of the self-drying jackets in Back to the Future.

There’s no real malevolent force in the episode - the nurses who want to nurse but are using clones as lab rats, and then, of course Cassandra.

Let’s begin with the nurses - I love their cat costumes. One of those cat/nurse hybrids was Martha Jones’ mum and you’d never know it! They seem very nice, orderly, but harbour the dark secret of a disease factory in the lower hospital levels. With hindsight, the story has the same themes as the Doppelgangers episode with Matt Smith. They’re called the Flesh and everything.

I didn’t quite buy the idea that a cocktail of cures managed to rid the clones of their diseases - particularly not just by the single touch of a hand. That seemed a little too convenient. Having said that, the Doctor stood in the lift under that waterfall of prescription - presumably he will never get sick from anything ever again.

Regardless, everyone was saved, except the strange little creature that was harbouring Cassandra. For the first episode of a new series, where you may be welcoming new fans to the story, I thought it was very brave to have such a lot of bodyswapping. We don’t yet know what our new Doctor is going to be like, and yet for this first episode, he was like… Cassandra. Very feminine and beating out a samba with his two hearts.

It was great fun and fabulous acting though, both David Tennant and Billie Piper did a great job of seeming inhabited. They were also brilliantly compassionate to Cassandra after she abandoned them, especially considering some of the things that she said - airing their dirty laundry out loud.

Talking of which, I remember quite a lot being made of that kiss before the episode first aired, but it was a bit weird. The Doctor said: “Still got it,” and walked away very happy with himself. It’s odd how he can be so good at flirting, and be so rubbish at the actual relationship stuff. See also: Idris and River.

The only other notable thing this episode was the Face of Boe making an appearance. Always confuses me that big old face. He seems lovely, but what the flip is it? I remember the Captain Jack connection, but other than that I don’t quite get it.

A good episode, a relatively subdued start to the series, with no big bad or overriding arc to follow. As mentioned above, the resolution was a bit too convenient, but it was ultimately quite a life-affirming story by the end, and I wasn’t left too disappointed.