John Barrowman plays Captain Jack Harkness
The Doctor might be the last remaining Time Lord, but he meets another
intergalactic time traveller when he and Rose arrive in Britain at the
height of the Blitz.
The pair land the TARDIS in 1941, after chasing a mysterious spaceship,
and meet dashing American serviceman Captain Jack Harkness - but he
isn't quite what he seems.
"Jack is actually a Time Agent - part of a kind of space CIA - and
he's trying to find two years of his memory that have disappeared,"
explains actor John Barrowman, who plays him.
"He's a rogue Time Agent and he knows he's done something in his past
and he's not sure what it is or whether it is good or bad because his
memory has been erased.
"But he's also an intergalactic conman and he starts off by trying
to con The Doctor and Rose. He tries to sell them something in order
to get money because that's what he does.
"He has conned a lot of people in the past. His method is to sell people
things that are not what he says they are - and then once he has got
the money he runs."
BBC viewers will remember John as a presenter (alongside Andi Peters
and Emma Forbes) on Live and Kicking in 1993 - but
more recently it is his stage career that has got him noticed.
He's starred in the musicals Chicago, Anything Goes, Sunset Boulevard,
The Phantom of the Opera, Beauty and The Beast, Miss Saigon and Evita
and last year appeared in the film De-Lovely with Kevin Kline.
Landing a role in Doctor Who was a huge thrill for John, who was born
in Glasgow but moved to America when he was nine, because he's always
loved the series.
"I'm a huge fan of Doctor Who," he says. "So this is a dream job."
The killer shop window dummies The Autons returned to Doctor Who in
2005 for Christopher Eccleston's first episode as The
Doctor, but it was their first appearance with Jon Pertwee in 1970 that
John recalls from his childhood.
"I remember the episode when the shop dummies came alive," he says.
"Mum had to hide me in her coat as we were going down Sauchiehall Street
in Glasgow because I wouldn't walk past the dummies as I'd been terrified
by the show a few days before!
"Later, after we moved to the United States, Doctor Who would be shown
in marathon runs on Sunday evenings and I'd stay up to watch it after
seeing Monty Python. It was a big part of my life and got me into sci-fi.
"When I was doing Sunset Boulevard in London, Jon Pertwee came to see
the show. He'd heard that I was a fan so he came backstage afterwards
and brought me a huge amount of memorabilia.
"They were things that he had that he said he didn't know what to do
with and he said he wanted to give them to someone who was a big fan
who would look after them. He was my first Doctor and was a lovely,
John has just returned from New York, where he has been filming the
movie version of the hit Mel Brooks musical The Producers, alongside
Nathan Lane, Matthew Broderick and Uma Thurman.
And it seems Doctor Who is known about in Hollywood. "Uma Thurman
came up to me one day and said: 'What's all this buzz about this new
girl (Billie Piper) who's doing Doctor Who?' She'd
heard all about the new series," says John.