The best things in life are Freema

But while the Hub and the TARDIS may share a studio space, the worlds in which their shows exist are markedly different in various ways. With Martha moving from tea-time to night time, did Freema set out to strike a more adult tone?

'Well, there's no swearing or nudity or anything like that,' she says. 'Because, obviously, there might be kids watching, and if we did that, they'd get a rude awakening.

'But while I wasn't trying to be any more adult in that respect, I did find myself thinking, 'Wow, I haven't once raised my voice, or screwed up my face in the way Martha did with the Doctor.' She was a bit more childlike and immature back then, but now she's seen a lot and can rationalise a lot more.

'There were no conscious decisions not to act like old Martha: it was all in the writing and the situations and subject matter. That naturally brought out a more controlled Martha, and it was all instinctive, which is how it should be.'

Someone else who has also had to find that balance when it comes to working across the two shows is, of course, John Barrowman. Was it a pleasure to be working with him again, after his own three-episode visit in the last series of Doctor Who?

'Oh, I love John!' Freema exclaims without a moment's hesitation. 'It was really, really nice to work with him again. He's like a friend and a dad to everyone, and I saw so many members of the group asking him about things, so many times. I think he's all-seeing and all-knowing!

But they're all so much fun - so different, but all on the same wavelength. There's always laughter on set, though they get the job done as well. They're always singing or making up songs together, and even though it's completely made up, they will finish each other's lines, because they're all so totally in the same zone! For me to be welcomed into that was such a joy.'

Of course, Freema wasn't the only guest star joining the fold for her first episode, Reset. So what was it like working alongside Hollywood - and Erinsborough's own - Alan Dale?

'He was so lovely!' Freema giggles, girlishly. 'He's so gorgeous and commanding that I actually melted a bit! But he was so refreshing to talk to, because he was so frank about the industry, and always ready to laugh at himself.

'He said that even though he's done 50 parts or whatever since he was in Neighbours, people still call him Jim! Then, of course, someone called him Jim on set, and I was just hooting! Had he not been able to laugh at himself, that could have been an awkward situation!'

Taken from the Official Torchwood Magazine on sale now