NOTE: Full spoilers for this episode of, “Doctor Who” are present in this review

After a highly divisive three series and collection of specials, Jodie Whittaker’s turn as the Thirteenth Doctor, the first female Doctor in the franchise’s canonical history, is finally coming to an end. “The Power of the Doctor” also happens to be the final episode showrun by Chris Chibnall, before OG New Who showrunner, Russell T. Davies returns to shepherd the series again with the upcoming Series 14. There are multiple eras ending with this Fall’s special episode of Doctor Who, and the show is pulling out all the stops to make sure that Whittaker’s final bow is a fittingly grand one. Yes, this is even considering all of the show’s former universe-scale business with the Timeless Child and the Flux.

“The Power of the Doctor” takes a rather unexpected turn for the forward-thinking-to-a-fault Chibnall era of Doctor Who, now all of a sudden digging into the series’ past with palpable glee. This special episode delivers a massive 90-minute storyline that pulls from almost every era of Doctor Who’s history, even going all the way back to the First Doctor’s Classic Who debut in the 1960’s, while cherry picking various companions and story nods to everything in between. This makes for one of the biggest, most fan-pleasing episodes in Doctor Who history, though does it manage to be one of the overall better Doctor regeneration specials? Er… Not totally.

Okay, to be fair, “The Power of the Doctor” is an incredibly exciting Doctor Who episode. It’s also hard not to smile at the sheer amount of former actors that Doctor Who managed to coax back for this regeneration special, with Sophie Aldred and Janet Fielding making the biggest mark here, reprising their roles as former Classic Who companions, Ace and Tegan, respectively. More than just a gimmick as well, Ace’s and Tegan’s returns eventually tie into an overarching theme that meshes effectively with the Doctor’s latest regeneration; How does one move on after they’ve left the TARDIS? New Who has touched upon this idea before, but it’s never dove so deep as it has here, eventually leading to a small fortune’s worth of legacy cameos that examine how the Doctor permanently touches the lives of their companions, and inspires each companion’s future long after their departure.

The staggering scope of this episode is also marked by the return of Sacha Dhawan’s excellent new take on the Master, boasting one of the arch-villain’s most ambitious plots yet! This scheme naturally incorporates the entire legion of Daleks and Cybermen, with Earth itself as the prize. Once again, all of the Doctor’s greatest enemies have their crosshairs pointed at her most treasured turf simultaneously, enacting separate plans in 1916 and 2022, in a bid to trap the Doctor within the agenda of the Master. There are many, many, many moving parts to the Master’s, “Three-step plan” to defeat the Doctor for good here, beginning with the Master comically being revealed as the Doctor Who universe’s real-world Russian mystic, Rasputin in 1916, which is part of a plan to create an entire planet out of Cyberman technology.

Oh, and it gets more complex from there. While Ace and Tegan team up with Kate and UNIT (yep, UNIT is back as if they never left, yet again), to try and keep the Cybermen (and the freshly-resurrected Ashad) at bay in 2022, Yas, the Doctor and eventually Vinder, making his own unexpected return here, try to investigate the Cyberman planet in 1916. Even then however, the Doctor quickly unmasks the Master as being behind the plot. Where’s Dan during all this, you may ask? Well, he has a close call after the Doctor frees a spacefaring train from Cyberman control at the start of this episode, and then decides he’s just… Leaving. Yeah, that’s it for Dan’s trip on the TARDIS, apparently. Just like that.

Dan’s hasty, unsatisfying departure is just one of several plot elements behind this regeneration special that feel rushed and messy. As much as, “The Power of the Doctor” is immensely thrilling to watch, and packed to the gills with Doctor Who fan service, it’s frustrating to see such an incredibly ambitious episode quickly collapse under its own weight, a problem that Chibnall also created last season with the ultimate execution of Doctor Who: Flux. Even more frustrating is that the Master’s ultimate plan remains fantastically devious in concept, wherein he successfully erases the Doctor from existence by forcing her to regenerate into him. This recreates the Doctor as their own archenemy, and sets the entire universe up for a permanent reign of terror and destruction, one that also permanently destroys the multi-millennia-spanning reputation of the Doctor all the while. I have to admit, as far as arch-villain plots go, that’s pretty amazing, and a very satisfying final strike by Dhawan’s standout Master!

“The staggering scope of this episode is also marked by the return of Sacha Dhawan’s excellent new take on the Master, boasting one of the arch-villain’s most ambitious plots yet!”

Sure enough however, the Thirteenth Doctor manages to endure, at the literal edge of regenerative oblivion. It’s at this point that the Doctor is revisited by several of her former incarnations, with David Bradley returning as the recast First Doctor within this vision, alongside surviving Classic Who Doctors, Peter Davison (Fifth Doctor), Colin Baker (Sixth Doctor), Sylvester McCoy (Seventh Doctor), and Paul McGann (Eighth Doctor). All the while, the Doctor’s enduring spirit manifests on Earth and in the TARDIS as an A.I. hologram for the surviving companions, as they attempt to outwit the Daleks, the Cybermen and the Master all at once. This includes allowing for some quick reunions between Tegan and the Fifth Doctor, and Ace and the Seventh Doctor, in more pleasing bits of Doctor Who fan service that should please longtime fans of the franchise.

Unfortunately, these heartwarming reunions between legacy Doctors and companions nonetheless remain undermined by an over-reliance on Deus Ex Machina’s throughout this episode. Most notably, the Doctor’s A.I. hologram is literally able to bounce around and fix things as the plot demands. An especially convenient Deus Ex Machina also comes via the surprise return of one of the Thirteenth Doctor’s own former companions around this point, Graham, who literally just appears out of nowhere in a Bolivian volcano to meet Ace! How in the bluest of hells did Graham get there without the Doctor’s help?! As cute as it is to see a hint of an off-screen romance forming between Graham and Ace, one that will surely continue after Graham hosts a support group for former companions (a moment that features yet more Classic Who companion cameos, as Bonnie Langford, Katy Manning and William Russell reprise their roles as Melanie, Jo and Ian, respectively during this scene), there’s still a few too many quick, easy solutions for such a definitive plot by the Master in this regeneration special. This hurts the Thirteenth Doctor’s final adventure much more than it should.

Even as the Doctor inevitably succeeds, and gets Yas to restore her body however, with some help from Jo Martin’s Fugitive Doctor (again appearing as a convenient hologram), the Master still manages to make one last strike against his mortal enemy, after his power source, an all-powerful energy beast called a Qurunx, accidentally strikes the Doctor with its planet-destroying beam. The Master is left for dead after this, inevitably to return on his own terms someday, but the damage to the Doctor remains done, even as the Daleks and Cybermen have once again been stopped. Yas and the Doctor are thus forced to say a heartbreaking goodbye, complete with Yas leaving the TARDIS herself in this episode, right as the Doctor regenerates again… Into David Tennant?!

In what’s easily the most shocking and enjoyable surprise of this episode (and that’s saying a lot!), despite Sex Education alum, Ncuti Gatwa already being confirmed as the next proper incarnation of the Doctor some months ago, it turns out that Gatwa is actually playing the Fifteenth Doctor, not the Fourteenth Doctor. The Fourteenth Doctor is instead another incarnation portrayed by Tenth Doctor actor, David Tennant, whose return is as much a shock to him as it no doubt is to the audience. Why has the Doctor suddenly regenerated into an already-spent incarnation? On top of bringing back arguably the most widely beloved New Who Doctor for the show’s 60th Anniversary (even if I, personally stand by Peter Capaldi’s Twelfth Doctor being the best-realized New Who Doctor at this point), Tennant’s return also sets up a compelling mystery for 2023’s upcoming batch of Doctor Who specials, with Gatwa seemingly taking over the role properly some time later, allegedly around Christmas 2023.

“The Power of the Doctor” definitely gets its emotional stakes right throughout its lengthy duration, as it ultimately wipes the slate clean for a new/old showrunner and Doctor incarnation in the near future. As much as the scope and heart behind Jodie Whittaker’s exit episode is overall superb however, the actual plotting of this regeneration special is a scattered mess that inevitably suffers from the sheer bloat of trying to combine pieces from the entire run of a decades-spanning television continuity. Exiting showrunner, Chris Chibnall should definitely be commended for his desire to make a big mark on Doctor Who history, but his run ultimately lacks the refinement and cleverness that often defined most of Steven Moffat’s episodes, especially those featuring the Twelfth Doctor. That issue is once again all too evident throughout Chibnall’s and Whittaker’s final episode. Longstanding Doctor Who fans should nonetheless find plenty to enjoy in this massive climactic outing for Whittaker’s Thirteenth Doctor, but the Doctor’s latest regeneration could have done with feeling significantly more sophisticated than the kitchen sink approach.