What can you tell us about the third series of Torchwood?
"I can tell you that Jack and the team find themselves in a completely different environment to what they're used to. Jack's past comes back to haunt him and the present team. It all sort of backfires on him and he has to clean up the mess that he and the government make."
Is it a literal mess? We've heard rumours of an explosion...
"It becomes a literal mess - that's all I'll say! If you've heard rumours of an explosion... well, it becomes a mess."
What do you make of the new format?
"It's a series of five episodes spread over a week. Personally, if it comes back for series four, I'd like to do more episodes. But we had to do something that created an impact when we moved to BBC One. It's like we're always under a test and I wish at some point they'd go 'you're fine! Stay where you are!' and that's what I'm looking forward to. But again, it depends on the audience."
How do you think fans will react?
"I think the audience will really like it. And if you've never seen Torchwood, now is the time to watch it. It's a one-off and you can just jump right in to it. It helps to know a bit of background, but you'll figure it out. Most people already know who Jack is, but for a non-Torchwood fan, you can definitely jump right in."
Is a fourth series something you'd be interested in?
And has it been discussed?
"We've talked about the future, but we're concentrating on series three right now. We're yet to find out about [series four], but I'd love to."
Can we expect to see you back in Doctor Who to bid farewell to David Tennant?
"Jack will always return to the Tardis if the Doctor's in need – to help save the planet or conquer an alien race trying to invade. That's all I can say! You know how secretive we are about all of that. Personally, as John, I would love to go back. If I'm asked, I'll be there in a second."
Do you approve of Matt Smith?
"It doesn't matter if I approve! But the audience will like him, I'm sure. He's an interesting looking guy and from my point of view, he's handsome! I think he's going to bring his own flavour and his own verve to it."
Have you met him?
"I have - I was doing some radio publicity for the show and he was brought into the press office to meet everybody and he made a beeline for me. We talked a little bit and he's a nice guy - he's really excited about it. After he left, I felt like I'd cheated on David! But in the world of Who, we're used to the Doctor regenerating and that's what happens."
Torchwood: Children Of Earth airs on BBC One later this Spring. John's new entertainment series Tonight's The Night begins this Saturday on BBC One.
In an interview with Digital Spy, John Barrowman expressed interest in making another series of Torchwood, and in appearing in more Doctor Who.
When asked is a fourth series (of Torchwood) something you'd be interested in? he replied Absolutely! We've talked about the future, but we're concentrating on series three right now.
When asked can we expect to see you back in Doctor Who to bid farewell to David Tennant? he replied Jack will always return to the Tardis if the Doctors in need - to help save the planet or conquer an alien race trying to invade. Thats all I can say! You know how secretive we are about all of that. Personally, as John, I would love to go back. If I'm asked, I'll be there in a second.
So ignore any rumours about a Torchwood without Jack, IMHO Torchwood is Jack, and is that a hint he is in the Doctor Who finale?