As the Doctor and Clara run, they notice there's an odd, metallic pinging sound coming from somewhere above them. The Doctor thinks it's the fuel rods warping. Indeed, they're warping so badly that they start to pierce through the hull, crisscrossing the hallway like the blades from a magician's trick. The Doctor and Clara narrowly miss being skewered multiple times, but Tricky is not so lucky. He's been kebabbed through the upper chest. "Just cut my arm off," he tells Gregor between screams of a pain he's not supposed to be feeling. "Tricky, you don't understand," Gregor says. The Doctor and Clara catch up to them. Gregor can't quite bring himself to tell the truth, so the Doctor does it for him and reveals that Tricky isn't an android at all. He has synthetic eyes and voice box, but everything else is human. Gregor comes up with some lame ass excuse about how he and Bram were bored, so they decided to convince their younger brother he was an android after he was badly injured in an accident and lost his memory.
Gregor cuts through the fuel rod to free Tricky, who inexplicably doesn't bleed out. Maybe the rod just pinned him in place without puncturing all the way through. They all make it to a room containing the TARDIS's power source, which the Doctor says they can only survive being exposed to for a minute or two. Gregor holds his scanner up to Clara: "Lancashire. Sass." Tricky and Gregor nearly come to blows over the whole fake android thing, but the Doctor breaks it up. "Ask yourself why he couldn't cut you up," he says to Tricky. "He has just one tiny scrap of decency left in him, and you helped him find that." Or else he just didn't want to be exposed as a fraud, which would have happened had he cut off his brother's arm. "Don't ever forget this," the Doctor says to Gregor.
Once everyone is on the same page, the Doctor leads them across a catwalk suspended under the Eye of Harmony. The Doctor explains it's a dying star, suspended at the moment of becoming a black hole. He goes on for a while about the engineering involved, like they're on a tour instead of trying to speed through before their flesh melts. They end up trapped on the catwalk when the creatures block off both avenues of escape. Clara demands the Doctor tell her what the creatures are. He refuses, saying he's just trying to keep her safe, but Gregor has no such obligation. He scans one of the creatures as it pounds on the door: "Lacashire... Sass. Identifiable substance... Clara." Clara realizes this means she burns under the Eye of Harmony. She gazes at her future self through a tiny porthole. "It isn't just the past leaking out through the time rift," the Doctor says. "I brought you here to keep you safe, but it happened again. You died again!" The Doctor has a moment of inspiration and feels he can change the future. The conjoined creatures are future Gregor and Tricky; if he can just keep the two brothers apart, then they won't meld together and become their future selves. Alas, this works out about as well as the time he tried to keep River from breaking her wrist. When Trick nearly plunges off the catwalk into oblivion, Gregor's moment of brotherly loyalty leads to them fusing together at the shoulder.