Billie Piper's new role as Doctor Who has fans of the show saying the same thing

Billie Piper's surprise return to Doctor Who as the 16th Doctor has sent fans into emotional overdrive - with many calling it a full-circle moment for the long-running sci-fi series.

The final episode of the current series, The Reality War, ended with Ncuti Gatwa's Doctor regenerating into a brand new form - revealing Piper as the latest incarnation of the iconic Time Lord.

Her appearance was kept tightly under wraps, with no previews sent to reviewers and simultaneous broadcasts taking place on BBC One, in cinemas, and via streaming on iPlayer and Disney+.

The twist shocked even longtime fans, who took to social media within minutes of the broadcast. "WHATTTTT," one user simply wrote on X (formerly Twitter).

Another joked: "If I had a nickel for every time a surprise Billie Piper cameo in Doctor Who made me scream, I'd have two nickels - which isn't a lot, but it's funny it's happened twice."

Others were flooded with nostalgia. "It's been 20 years and Rose Tyler is still my favourite companion," one fan tweeted. "She was my first after all. In whatever incarnation Billie Piper shows up as, it just reminds me of being a teen again, being introduced to this wild British TV show on the Sci-Fi Channel."

Another wrote: "Me in 2005: watching Doctor Who for Billie Piper. Me in 2025: still watching Doctor Who for Billie Piper."

Piper, now 42, originally played companion Rose Tyler in 2005 alongside Christopher Eccleston's Ninth Doctor. She went on to appear opposite David Tennant and was later revealed to be the mythical "Bad Wolf" - a mysterious, universe-shaping figure. Now, she's taken the role full circle by stepping into the shoes of the Doctor herself.

"It's no secret how much I love this show," Piper said earlier in a statement to the BBC. "I've always said I would love to return to the Whoniverse, as I have some of my best memories there. So to be given the opportunity to step back on that TARDIS one more time was just something I couldn't refuse. But who, how, why and when - you'll just have to wait and see."

The regeneration marks the departure of Ncuti Gatwa, who served as the 15th Doctor. He also reflected on the experience: "You know when you get cast, at some point you're going to have to hand back that sonic screwdriver, but nothing quite prepares you for it. This journey has been one that I will never forget, and a role that will be part of me forever."

The finale also featured a surprise guest appearance by Jodie Whittaker, the 13th Doctor, as the story veered into alternate universes - a narrative move fans say could pave the way for even more crossovers and familiar faces.