“It’s exciting as someone who grew up watching Doctor Who. It’s very exciting whenever there’s a rebirth of the show – that’s an exciting moment anyway. But because Jodie’s a friend, and Chris is a friend, it’s exciting on so many levels.”
Tennant, who in 2008 announced live on TV that he was vacating the Tardis, admits it’s strange to watch the show as someone who once starred in it.
“It’s bizarre because it’s a show I’ve watched all my life, then I ended up being in it which was weird in the first place, and now I’m out of it. There’s kind of a journey back to being an observer again,” he added.
“But five minutes in I was just watching it as a fan again. I’d forgotten that I knew them and they were my mates. I was like, ‘This is fun! This is exciting!’”
Despite being close friends with the people at the helm of Who, Tennant says he’s not privy to any spoilers – and as a super-fan, he wouldn’t want to hear them anyway.
“I knew they were shooting it and I talked to Jodie and Chris a little bit while they were making it and since, but I didn’t know anything about it, it’s all new to me,” he explained.
“I don’t think they’d tell me anything,” he added, “but I also don’t want to go there. I want to experience it like everyone else.”
And while Tennant – who is now starring BBC4’s moving There She Goes – may have handed over his sonic screwdriver, he admits he’s still mobbed by Whovians at events – which sees him having to go incognito when visiting the various Comic Cons around the world.
“I do feel now the geek as inherited the Earth,” he joked. “It’s a shame I can’t go as a fan because I’d love to go to all the comic book stalls and meet the guys that draw Spiderman – that would be my idea of heaven! But I have to lurk backstage.
“The other option is to put a mask on but then you get very hot. Maybe I should put a Jodie Whittaker mask on? That’s what I need to invest in.”
Doctor Who continues on BBC1 on Sunday 14th October at 6.55pm
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