It took the Doctor a beat too long to notice that the Master was offering the laser to him grip-first. The Master looked at him pointedly and extended his arm further, until the Doctor took the screwdriver out of his hand. The Master said, "I switched off the isomorphic recognition. You can test it if you don't believe me."
The Doctor slipped the laser screwdriver into the inside breast pocket of his jacket, where he kept his own sonic screwdriver, only then realizing that he'd left it in another universe. He hoped the Master didn't catch his look of surprise. "I trust you."
"You don't, and you shouldn't. Don't be dumb and sentimental about this, and don't lie to me. You may fool your human companions, but I can see right through it."
The Doctor wanted to smile and say, 'So, you're my companion now?', but immediately thought better of it. He needed to think better, sharper, and one step ahead of the Master if he had any hope of helping the man. A part of him doubted if he was capable of the task. "Shouldn't we be getting back to Amy?" asked the Master, nervously running a hand through his short sandy-colored hair.
"Good idea."
Off to a great start with that thinking thing, he thought.
The Doctor landed the red TARDIS inside the blue, in an obscure room used for storage. "I'm sorry," he said to the Master, "but there's a situation that needs tending to before I can help you."
"I gathered as much."
The Doctor gestured for the Master to walk ahead of him out of the cargo hold. They moved down a passageway and entered a chamber that was completely empty and round, with walls that were glowing a soothing pinkish-gold. "I didn't realize every TARDIS came with a Zero Room," said the Master, perking up slightly.
"Does it dampen the drums at all?"
The Master closed his eyes. "A bit, yes."
"Good."
The Doctor gently rested a hand on the Master's shoulder and guided him further into the room. The Master looked at the hand, then his gaze ascended up the arm. He inhaled deeply. "What is that…smell, or energy?"
"It's called 'Dual Space', the latest scent from Argolis. Slightly radioactive."
The Master looked very confused. "It's…nice," he said, hardly aware of what he was saying.
The Doctor took a step back and quickly changed the subject. "I hate to lock you in here, but I don't see another option right now. I promise I'll be back as soon as I can."
"Am I responsible for Rory's disappearance?" the Master asked abruptly.
The Doctor crossed to the door and paused on the threshold. "Quite possibly. I think when you created that tear in space-time while targeting my TARDIS, a mirror-tear was also created, right where we were. You know how the universe loves quantum entanglement. I sensed it happening and tried to dodge it, but Rory got hit by the edge of it. He pushed Amy out of the way, actually."
"I didn't mean for that to happen."
"I know. As far as I can tell, nobody was hurt."
The Master was facing away, staring at the wall. "Go help your friends," he said.
The Doctor left, double dead-locking the door behind him, so it could only be opened from the outside. He wove through the corridors of the TARDIS, until he reached the bridge, where Amy was pacing impatiently. She started when she caught sight of him. "Don't sneak up! Where's the other one?"
"Safely secured in the basement."
"Not creepy at all, that. So, he's really a Time Lord?"
The Doctor nodded.
"You said you were the last."
"I thought I was. I didn't think I'd ever see him again."
"He wants you to help him get rid of the drums. What drums?"
"When he was eight years old, he was brainwashed by the leader of Gallifrey using a four-beat drumming pattern…and it drove him mad. I don't know how, but I'm going to find a way to remove that programming."
"Did you know him, on Gallifrey?"
"Yes. We're the same age."
"Oh. You never mentioned him."
"I don't like dwelling on bad memories."
"Well, since he's coming along, can we go now? I want my husband back."