As soon as One exits, the glassy CGI being identifies him as The Doctor of War, and it offers him a gift: the chance to speak with “her, again” in exchange for the human on board.
“Her,” turns out to be Bill Potts, back from the dead, or so it seems. It’s a gift for Twelve, who exits the Tardis and gives her a massive hug. But, as we’ve learned, never trust a hug. It’s just a way to hide your face. Happy as he is to see her, Twelve isn’t convinced that Bill is still alive. “My friend Bill Potts was turned into a Cyberman. She gave her life so that people she barely knew could live. Nobody imitates Bill Potts. Nobody mocks Bill Potts.”
And Bill can’t remember how she got there, which is our first clue that she’s some sort of apparition. The glass woman identifies herself as “Testimony,” a being (beings?) from the distant future who come back in time to harvest memories from people at the very moment of their death. The World War I Captain, it turns out, was interrupted right as he was supposed to die, and so the Testimony needs to make sure that he goes back and dies correctly, and it’s willing to give them Bill Potts in exchange.
Ever the honorable soldier, the Captain leaves the Tardis, happy to make the ultimate sacrifice to save Bill’s life, but Twelve refuses to give him the chance; instead, they’ll all escape, jumping out the hatch in the floor, sliding down chains to the roof of his Tardis, and then jumping to the ground. The Testimony takes up his Tardis, but with two Doctors, we get two rides. The gang makes their way into the vintage, bright white Tardis, for more of One’s old-timey 1960’s uncle sexism and Gatiss’s delightfully stiff-upper-lipped 20th century Brit: “These police boxes — they’re ever so good, aren’t they?”
Between the two of them, the Doctors notice that the glass woman — the Testimony — had an asymmetrical face, which indicates that she was once a real person, or at least based on one (well, Twelve would have noticed if the sunglasses weren’t disrupting his vision). And so Twelve flies the Tardis to the planet of the world’s biggest database to figure out who she is. The planet seems to be populated entirely by creepy facehugger monsters until the real primary resident is revealed: Rusty the Dalek, who dutifully disarms himself (no extermination plunger) in order to peacefully chat with Twelve. Rusty has been programmed to hate the Daleks, and so it’s willing to help Twelve identify the woman from Testimony: someone from New Earth named Professor Helen Clay.
Thanks to the Dalek network, Clay’s avatar begins to explain what Testimony is: a system that uploads people’s memories at the moment of their death so they can continue to “live” as glass avatars, like a version of Black Mirror’s tech from “I’ll Be Right Back.” And so, of course, that’s what Bill is. But, the Testimony is surprisingly, not sinister at all. “Not an evil plan,” Twelve says. “I don’t really know what to do when it isn’t an evil plan.” Bill isn’t in denial; she knows exactly who, and what, she is and she’s okay with it. “What is anyone supposed to be except a bunch of memories? I’m Bill Potts, and I’m back.” (Recap continues on next page)