Doctor Who Reveals David Tennant’s Regeneration With a Huge Twist

David Tennant’s return to Doctor Who as the Fourteenth Doctor concludes in Doctor Who with his regeneration into Ncuti Gatwa’s Fifteenth Doctor… or does it? SPOILERS for Doctor Who Special 3, “The Giggle,” follow. Doctor Who fans knew that David Tennant’s return to Doctor Who was a limited engagement spanning only the three Doctor Who 60th-anniversary specials. However, his regeneration into the Fifteenth Doctor took a turn that few could have expected. It is a tradition that each Doctor regenerates into the next, handing over the mantle to the next face of Doctor Who. This time, things went differently.

The Fourteenth Doctor didn’t regenerate. Instead, he bi-generated. The Fifteenth Doctor didn’t replace the Fourteenth Doctor but popped out of him in one of the most unusual regeneration-ish sequences Doctor Who has ever done. You can watch the scene below.

What is bi-generation in Doctor Who?

As Doctor Who Special 3: “The Giggle” explains, bi-generation was only a legend among the Time Lords. Then again, so was the Timeless Child, which turned out to be true.

According to Russell T Davies (as explained during the latest installment of the Official Doctor Who Podcast), the bi-generation doesn’t apply only to the Fourteenth Doctor. Each version of the Doctor that came previous to it also bi-generates, splitting off a second version of themselves that can get closure. These versions of the Doctor are, presumably, the older versions of these Doctors that appear in Tales of the TARDIS. It’s also possible that these Doctors are the elder versions of the Doctor that have popped up, and possibly even explain the appearance of Tom Baker’s The Curator in the 50th-anniversary special, “The Day of the Doctor.”

But what this does for Doctor Who‘s future is allow Gatwa’s Doctor to have a fresh start. Rather than carrying around the burden of guilt that the Fourteenth Doctor has from the Flux, the Fourteenth Doctor is free to work that out with his ad hoc family. Meanwhile, his future self, the Fifteenth Doctor, already benefits from that rest and embarks on new adventures.

The upcoming season of Doctor Who really will be a new beginning. It all starts with the Doctor Who Christmas Special.

When is the 2023 Doctor Who Holiday Special?

The Doctor Who Holiday Special follows David Tennant’s run as the Fourteenth Doctor in the three Doctor Who 60th-anniversary specials. Gatwa and Gibson’s debuts in the 2023 Doctor Who Christmas Special, titled “The Church on Ruby Road,” will lead into Doctor Who‘s new season, the first streaming on Disney+. It will debut in 2024 and has already wrapped filming. Gatwa and Gibson’s second Doctor Who season will follow, presumably in 2025. That season is in production now.

Gatwa’s debut should be the perfect jumping-on-point for new Doctor Who fans, but anyone looking to catch up on modern Doctor Who should check out our Doctor Who streaming binge guide. The three Doctor Who 60th-anniversary specials are streaming on Disney+ now.