Presenter Rylan Clark said he had to keep his casting in an upcoming Doctor Who episode a secret for a year.
The TV and radio star, 36, is due to play himself in an episode of the popular BBC show in which he is one of the presenters for the Interstellar Song Contest – a mimic of the Eurovision Song Contest.
The episode is due to air on 17 May, the same night that the Eurovision Song Contest Final is due to take place in Basel, Switzerland.
Describing himself as a "massive Whovian", Clark said: "It was so hard to keep the secret, and I've been sat on it for a year.
"I told a few key people who had to know but we’ve really kept it super private.
"I played myself but also added a bit of Caesar (Flickerman) from the Hunger Games for good measure."
Caesar refers to the character from the Hunger Games franchise, played by Stanley Tucci, who is an eccentric presenter who interviews the tributes and commentates on the Games which see children fight in an arena to their death.
According to Clark the episode is "out of this world", with lots of twists while paying close attention to the details of the actual song contest it is based on.
He added: "People can expect to see everything they love about Doctor Who.
"Also, from working on actual Eurovision itself, there were so many similarities – the attention to detail was amazing.
"Expect the unexpected – it’s probably the most twisty one of the whole season."
Ncuti Gatwa, known for his breakout role as Eric Effiong in the hit Netflix series Sex Education, plays this season’s Doctor alongside Varada Sethu who plays the Companion, Belinda Chandra.
Juno Dawson, a writer on the series, said she was approached by producer Russell T Davies to help write the episode.
She said: "In 2022, Russell asked how I would feel about doing Die Hard meets Eurovision. I couldn’t turn that down.
"Russell initially pitched the bare bones concept of Eurovision meets Die Hard, which were two things I knew really well.
"Then, I went away and pitched a plot, and it hasn’t really changed all that much.
"Obviously, there was a lot of discussion between myself, the producers and Russell.
"But it’s still those two things. What would happen if an enemy faction planned an attack on the Eurovision Song Contest in space?"
The Eurovision Song Contest Semi-Finals take place on 13 and 15 May, and will be shown live on RTÉ 2 and RTÉ Player from 8pm. The Grand Final takes place on Saturday, 17 May, and will be shown live on RTÉ One and RTÉ Player from 8pm.
