Summary

• In the Doctor Who anniversary special, "The Giggle," the Doctor undergoes a unique "bi-generation" instead of a traditional regeneration, resulting in the creation of two separate beings.
• The Toymaker, the antagonist in the special, is banished from existence by the Doctors, but hints at his potential return through his legions, possibly foreshadowing the Doctor Who Christmas Special.
• David Tennant's return as the Fourteenth Doctor in the anniversary specials sets up the potential for a UNIT spinoff, while Ncuti Gatwa's adventures continue.

This article contains spoilers for the Doctor Who anniversary special, "The Giggle"The final Doctor Who 60th anniversary special, "The Giggle," saw the Doctor defeat the Toymaker - with the most shocking regeneration story to date. Regeneration is the secret of Doctor Who's success. In-universe, it is a lottery, with the Doctor never knowing what to expect. In reality, though, regeneration allows Doctor Who to continually reinvent itself for every generation.

The Doctor Who 60th anniversary specials had already been set up as a surprising regeneration tale. The end of "The Power of the Doctor" saw Jodie Whittaker's Thirteenth Doctor unexpectedly regenerate into a familiar face. David Tennant's return as the Fourteenth Doctor served as the great mystery of the Doctor Who anniversary specials, although in truth most viewers were just happy to have Tennant and Catherine Tate's Donna Noble back. Another regeneration was always on the cards for this story, though, given Ncuti Gatwa's Fifteenth Doctor was confirmed to appear in the specials. But, surprisingly, things took a twist that had never been seen before in Doctor Who history.

Doctor Who's Anniversary Specials Introduced The Idea Of Bi-Generation

The final Doctor Who anniversary special, "The Giggle," saw the Toymaker attempt to force a regeneration. The Doctor had challenged the Toymaker to win the best of three, but the Toymaker pointed out that both games to date had been with different Doctors. Still furious because the Doctor had dared challenge him, the Toymaker insisted a regeneration needed to be forced so the games could continue. He shot the Doctor through one heart with the galvanic beam.

But the Toymaker's forced regeneration went drastically wrong, because the Doctor didn't regenerate at all; he went through what he called a "bi-generation," which is apparently a Time Lord myth where a regeneration instead results in the creation of two separate beings who can go on to live their own lives. According to Russell T. Davies, as revealed in Doctor Who Unleashed, this had a ripple effect on the Doctor's every regeneration - creating splintered timelines in which each incarnaton of the Doctor did not regenerate. This was arguably set up in Doctor Who's Tales of the TARDIS spinoffs, which featured older versions of classic Doctors, with Sylvester McCoy's Seventh Doctor claiming it is tied to timelines. IIt's possible bi-regeneration can only be done by a being who has unlimited regeneration energy, such as he Timeless Child.

It's possible bi-regeneration can only be done by a being who has unlimited regeneration energy, such as the Timeliness Child.

How The Doctors Defeated The Toymaker

"The Giggle" essentially became an unexpected Doctor Who multi-Doctor story - tradiitionally associated with anniversary years. The Fourteenth and Fifteenth Doctors teamed up against the Toymaker, and they challenged him to a game that gave them a decided advantage; a simple game of catch the ball. They were able to team up against him, frequently tossing the ball to one another so the Toymaker couldn't predict the angle it would come from. They won the game, and the Toymaker faced defeat.

With the Toymakers defeated, the Doctors banished the Toymaker from existence, essentially returning him to his own dimension beyond the boundaries of reality. Although the Doctors were triumphant, the Toymaker hinted he could still potentially return; he swore to the Doctor that his legions were coming. This may well foreshadow the little that is known of the Doctor Who Christmas Special, in which Ncuti Gatwa's Fifteenth Doctor will encounter goblins; like the Toymaker, they could also be creatures of superstition as much as science, although the trailer has certainly shown them in a spaceship.

The Doctor Who Anniversary Specials Set Up The Master's Return

In an earlier scene, the Toymaker celebrated his triumphs by bragging to the Doctor about all the beings he'd defeated. He had made the Doctor's past a jigsaw puzzle, he declared, which may be a rather amusing way of explaining all Doctor Who's continuity problems - multiple destructions of Skaro and Atlantis, contradictory claims about historical figures, and of course the unimaginable number of adventures told in tie-in media. This could even explain some of the various contradictions inherent in the Timeless Child retcon, But, having boasted about his rewriting of the Doctor's past, the Toymaker went on to celebrate the fact the dying Master had lost a game and been transformed into his gold tooth for all eternity.

The Toymaker was banished from reality, but his gold tooth was left behind. "The Giggle" saw it picked up by a female hand, but it was unclear whose - presumably someone in UNIT. This clearly sets up the Master's return on 21st century Earth, an even more exciting idea given the potential of this latest UNIT team. Amusingly, the first of the Doctor Who anniversary specials saw Donna insist a man with a goatee should never be trusted, which seemed to foreshadow the Master as well.

Doctor Who Finally Explains David Tennant's Return - & Sets Up A Potential Spinoff

The Doctor Who anniversary specials finally explained why David Tennant returned as the Fifteenth Doctor; because there's a sense in which the Doctor had unfinished business. The Doctor is the one who runs, never taking the time to fully heal from the trauma they have suffered, never settling down and knowing the adventure of a family life. Donna offered the Fourteenth Doctor something he had never had before; a family. He chose to stay on Earth with the Noble family, but will presumably continue to have adventures given he has such strong ties to UNIT.

There have been repeated rumors of a UNIT spinoff, and this now seems more likely than ever before - but a spinoff starring David Tennant's Fourteenth Doctor on Earth. Such an Earthbound series would actually parallel Jon Pertwee's Third Doctor era; his incarnation was exiled to Earth for a couple of years, developing a loose family around him in an earlier UNIT team. It's exciting to see Doctor Who set this up again, with such a much-loved incarnation of the Doctor as Tennant.

David Tennant & Ncuti Gatwa Each Have A TARDIS

At first, the Doctor Who anniversary specials seemed to be setting up a scene in which the Doctors decided who should leave with the TARDIS. But Ncuti Gatwa's Fifteenth Doctor realized the laws of reality were still in flux due to the Toymaker's presence, and that the Doctors had not claimed their prize. He knew exactly what they should get; he used a hammer to strike the TARDIS, and it too was duplicated. Now both the Fourteenth and Fifteenth Doctors have a TARDIS, almost identical but with one key difference - Gatwa's has an additional jukebox.

David Tennant's Fourteenth Doctor has stayed on Earth with the Noble family. Ncuti Gatwa's Fifteenth Doctor - already demonstrating a commanding presence - has headed off in the TARDIS for adventures anew. His story will continue in the Doctor Who Christmas Special, "The Church on Ruby Road," where he meets with his first companion - Millie Gibson's Ruby Sunday. It will be thrilling to see what happens next.