Actor Dan Starkey had a strange experience in Sheffield - the former Doctor Who regular found himself in the city at the same time as new Doctor Jodie Whittaker and the Tardis itself!
Dan was in final rehearsals for Frost/Nixon at the Crucible at the same time as the Doctor Who crew were filming over the road at Park Hill flats.
Dan played the Sontaran warrior Strax and other Sontaran characters in the show, alongside the Doctors played by Matt Smith and Peter Capaldi.
The Sontarans are a small, warlike race who have a bullet-headed look.
In Frost/Nixon, the battle is between the disgraced US president Richard Nixon and the British TV star David Frost, who managed to get the rights to an exclusive US TV interview where he famously questions Nixon about the Watergate scandal that caused his fall from grace.
Dan said: “I’m playing Swifty Lazar, who is Nixon’s literary agent. He is responsible for setting up the interview shown in Frost/Nixon. He got one of the biggest publishing deals of the time for Nixon’s memoirs.
“As part of that package Nixon was going to do an interview with the Paxman of his day, the CBS TV network hatchet man.
“Then he realised that David Frost had asked for an interview and he thought Frost was a bit of a lightweight and thought it was possible they could put the screws on him and get a lot more money out of him.”
Swifty has only a small role in the play but Dan said he was an amazing, larger-than-life character. “He was an astonishing Hollywood deal-maker who had been going since the 30s. He was nicknamed Swifty by Humphrey Bogart when he cut three deals for him in one day.”
Dan had his head shaved for the role and thinks he looks like like cartoon character Mr Magoo as Swifty.
However, he’s been used to a more thorough makeover for Doctor Who, when make-up and costume teams had to spend three hours transforming him into a Sontaran.
He wore either a space battle suit, with trousers that took 10 minutes to get into, or a James Bond Odd Job-style butler’s outfit.
Dan is always pleased at sci-fi conventions when cosplay fans turn up dressed as Strax but said it doesn’t happen often because of the complexities of creating the look.
He also writes for the Doctor Who audio series and said: “I wrote a Doctor Who story for Tom Baker. It was exciting writing for one of my childhood Doctors. He liked it!”
That story will be out in May.
Dan doesn’t know if Strax will return to Doctor Who but said he’d love to go back, quipping: “Have rubber suit, will travel!”
He has also been a regular on CBBC comedy sketch show Class Dismissed, playing five or six different characters, "but never with my own face". So he's done lots of TV but is hardly ever recognised!
Frost/Nixon ends its run at the Crucible, Sheffield, tomorrow, Saturday, March 17. Box office: www.sheffieldtheatres.co.uk