Last Night’s Doctor Who Season 12 Cliffhanger Explained

Doctor Who season 12 reached its penultimate episode last night with “Ascension of the Cybermen,” the first of a climactic two-parter. As you’d expect, then, the stakes built up across the hour until things reached a peak with the shocking cliffhanger. A cliffhanger that saw the return of both the Doctor’s mortal enemy the Master and an unexpected connection to the duo’s homeworld, Gallifrey. So, let’s recap how everything fit together.

The episode took the TARDIS team to the far future, in the wake of the Great Cyber-War, in which humanity and the Cybermen have all but wiped each other out. The fam are separated into two, though their end goal is the same – to get to Bo Sharmas, where something called the Boundary is situated. While Graham, Yaz and some survivors are trapped on a Cyber-ship, which harbors an army of warrior-class Cybermen, the Doctor and Ryan find Bo Sharmas, who’s actually a lonely hermit, not a place, that guards the Boundary.

It turns out that the Boundary is a wormhole in space/time which we’re told the last of the human race has fled through to escape the Cybermen. As the Time Lord nears the portal, it’s revealed what lies on the other side – Gallifrey! The Doctor marvels at the impossibility, just as the Master hops out the wormhole and announces that things are about to change forever.

We’re left with a ton of questions, then. First of all, Bo Sharmas notes that he’s never seen the Boundary look like this before, so we’re unsure whether it’s always led to Gallifrey. If it has, does this mean humanity will repopulate the destroyed world? Remember, the Master wiped out the Time Lords again, as revealed in “Spyfall: Part Two.” Will the Cybermen invade the planet if they follow the humans to Bo Sharmas? And how the heck does the subplot of that immortal policeman in 1950s Ireland fit into it all? Find out when Doctor Who season 12 concludes with “The Timeless Children” this Sunday, March 1st on BBC One/America.