'Doctor Who' Upgrades Its Mysteries In The Action-Packed 'Ascension Of The Cybermen'

In a series that so frequently contradicts and corrects itself like Doctor Who, can there be any such thing as canon? Even the question of character development is up in the air, as a time-traveling protagonist who has been on and off the air for upwards of 50 years can only change so much before the story becomes untenable. All of this is leading up to me saying I'm intrigued by whatever showrunner Chris Chibnall is building up to in the penultimate episode of Doctor Who season 12. Because, despite the amorphous, ever-shifting nature of Doctor Who, it feels game-changing.

"Ascension of the Cybermen" picks up right after the events of last week's excellent "The Haunting of Villa Diodati," showing the Doctor and Team TARDIS landing in a far-future where the remnants of humanity are barely holding on after a universe-devastating Cybermen war. And without the Doctor's help, humanity could be extinguished altogether. But as the Doctor and Team TARDIS jump to action in what is the most blockbuster sci-fi episode of the Jodie Whittaker era, Doctor Who is not against introducing several more baffling, head-scratching mysteries. Next week's season finale has a lot to answer to.

"That which is dead can live again...in the hands of a believer," the Lone Cyberman narrates at the beginning of the episode, in the first of many flowery monologues that the villain will spout in this episode. The Lone Cyberman's mission is very simple: to bring back the Cyber Empire in all its glory and destroy the universe — your standard evil villain stuff. It's the mysterious surrounding the Lone Cyberman that are still yet to be answered. That's the difficulty with the first part of a season finale two parter: keeping your audience engaged while leaving things open for the final episode. "Ascension of the Cybermen," while frustrating at times in the number of mysteries it introduces, maintains this balance well. The episode does so by giving us one of the most action-packed, blockbuster-sized hours to date, with the Doctor and Team TARDIS arriving in the very far future, in the aftermath of the Cyber War, to help out the dwindling members of humanity.

Things are looking bleak for humanity, as all have been wiped out except for a ragtag group of refugees who have fled from the Cybermen their entire lives. But even their meager numbers start to dwindle after the Doctor's efforts to save them are thwarted by an attacking horde of Cyber drones (essentially, flying Cybermen heads), and the group is forced to scatter. Doctor Who rarely commits full episodes to scenes of war as "Ascension of the Cybermen" does — saving those big blockbuster sequences for finales or specials — but Whittaker is fantastic in war mode: intense, panicked, and truly at a loss. The 13th Doctor has sometimes over-relied on her companions in the past, falling back on them as a source of comfort and trusting them in even the most dangerous situations. That's what makes it so surprising, and makes the stakes feel so real, when she orders them to flee, lamenting, "I've been so reckless with you."

Yaz and Graham make it to the ship that three members of the group had been trying to salvage, while Ryan gets separated and reunited with the Doctor, whose noble face-off with the Lone Cyberman doesn't go exactly as planned as he now comes flanked by two other Cybermen. The two save the teenaged member of the group of refugees from the Lone Cyberman, who had just mercilessly killed their leader, and run off to steal a Cybership. The teen, Ethan (Matt Carver) manages to hijack the ship even faster than the Doctor (which, in addition to him not being affected by the Cyber warp travel like Ryan, is very curious), and the three speed off into space while while Graham and Yaz are stuck in the escape vessel with former nurse Ravio (Julie Graham), pessimistic Yedlarmi (Alex Austin), and a young woman named Bescot (Rhiannon Clements). With all the focus on action, the episode barely has time to introduce these new characters, let alone let us grieve for the ones that are quickly killed in the fray. The new characters all blend together somewhat, with the exception of the tough-as-nails Ravio, which ends up being a major detriment for the episode.

Do Cybermen dream of electric sheep? Judging by the flashbacks that follow the mysterious Brendan (Evan McCabe) — a young man who as a baby is found by a farmer in what appears to be early 20th century Ireland (but could easily be the early days of the human settlement we saw before) — maybe they dream of actual sheep. In a Superman-esque origin story that is interspersed throughout the episode, Brendan is discovered as a baby and raised by a farmer and his wife in a sweet and mundane montage whose twinkling tone calls to mind the sinister sequence in season 4's "Forest of the Dead," when Donna is trapped in an alternate reality. And apart from his origins, Brendan's life seems pretty ordinary, aging like a normal adult before he lands his first job as a "guard." But soon strange things begin happening, as Brendan takes a bullet to the chest while chasing a desperate thief and miraculously survives that and a 50-foot cliff fall, baffling his doctors and his father.

We don't learn much more about who Brendan is, though the biggest implication is that he is the Lone Cyberman before his conversion. Indeed, what the Lone Cyberman says of his early days seems to indicate as much; hijacking the comms of the Doctor's Cyber ship to speak about his vengeful quest to revive the Cyber empire after being denied as a recruit. In the final flashback we see of Brendan, he is an old man, retiring from his job as a guard and taken to a back room by his boss and father who have, oddly, not aged. They hook him up to a contraption with headphones that look a lot like a Cyber helmet, and thank him for his service before electrocuting him.

As the escape ship unsteadily makes its way through space, Yaz and Graham learn that the group of refugees is trying to make their way to the last haven in the universe, Ko Sharmus, where they can enter a mysterious "Boundary" that will supposedly transport them out of the galaxy and out of the reaches of the Cybermen. But their dreams are soon dashed when the ship's engines explode, leaving them on life support. Yaz and Graham manage to rally the despondent group and convince them to channel the last bit of their life support into propelling the ship toward a massive nearby Cyber carrier laying dormant in the remnants of an epic battle. They miraculously manage to land safely in the carrier, but are soon followed by the Lone Cyberman, who awakens the thousands of dormant Cyber warriors hidden in the ship.

Up until now, the episode's uneven pace and baffling number of mysteries threaten to make "Ascension of the Cyberman" a confusing mess — the action sequences were stellar, but the world-building and characters left something to be desired. But the introduction of Ko Sharmus (Game of Thrones' Ian McElhinney, oozing prophetic gravitas), who the Doctor discovers is actually a person and not a place, brings the episode together. Ko Sharmus had long lived near the Boundary waiting to shepherd human survivors to safety, but had given up hope of seeing any humans again — the joy shining through on his face when the Doctor and co. arrive. But as Yaz and Graham's group grapple with whether to bring a ship full of Cyber warriors to the last remaining haven for humanity, the Doctor discovers what the Boundary really is: a portal to the destroyed Gallifrey. Just as this realization dawns on her, the Master jumps through. "Be afraid, Doctor. Because everything is about to change," he says gleefully. It's quite a cliffhanger that leaves many (almost too many) questions for the season finale to answer. Will Yaz and Graham survive the attacking Cyber army? Probably. But as for the rest, who knows? Who is Brendan? Who is the Timeless Child? Are the humans escaping through the Boundary actually the descendants of the Time Lords? Time is getting even more wibbly-wobbly than ever.