Actress Freema Agyeman has talked about her excitement at becoming Doctor Who's new assistant as the third series of the hit BBC sci-fi show begins filming.
Agyeman (l) had a minor role in the last Doctor Who series
"I am still pinching myself," said the 27-year-old Londoner, who plays medical student Martha Jones opposite David Tennant's Doctor in the programme.
"It's been nerve-wracking, but David has been brilliant helping me adjust."
Writer and executive producer Russell T Davies has promised "new thrills, new laughs and some terrifying new aliens".
"The Doctor and Martha are destined to meet William Shakespeare, blood-sucking alien Plasmavores, The Judoon - a clan of galactic stormtroopers - and a sinister intelligence at work in 1930s New York," he said.
'Time and space'
Agyeman appeared in the penultimate episode of the second Doctor Who series, playing a minor character who suffered at the hands of the Cybermen.
After completing her role, she was invited back to audition for the role of the Doctor's new companion.
"I am really looking forward to travelling through time and space with [Tennant] over the next eight months," the actress added.
Agyeman's character replaces former assistant Rose Tyler, who was written out at the end of the second series after Billie Piper decided to leave the show.
Before the third series is broadcast next year, the Doctor will be seen in a Christmas special alongside comedienne Catherine Tate.