"Ah, Doctor. Good news! I've... oh." He took a closer look at the Doctor's face. "Am I in trouble?"
"How did you do it?" the Doctor asked nervelessly. "How did you alter your programming so you could torment that girl?"
The Master cast a glance past him at the outdoors. He shrugged disinterestedly.
"Oh, that. You underestimate the subtlety of your own programming, Doctor. I can't stab you with a pin out of spite, it's true, but I could give you a hypodermic injection to save your life if the need arose. Likewise, I can do what I like to your new friend as long as it's for the greater good."
"The greater good?" repeated the Doctor, dripping contempt with each word.
"Certainly. The genetic sample you gave me was inadequate. I simply used the girl as bait to capture a complete specimen. And I think when you see the results I've..."
"Stop it!" At the bite in the Doctor's voice the Master fell silent with a condescending roll of his eyes. "How could you ever have thought I'd let you get away with this? What you did to her..."
"Oh, come now, it was just a scratch. And I netted the unpleasant creature before it could fix its sucker onto her. She's fine."
"Fine?" Pace by pace, the Doctor drew nearer to his old friend and enemy, his face riven with fury. "She's terrified! Traumatised!"
"Nonsense." The Master didn't stir a muscle at the steadily diminishing gap between them. "She's human. You know what they're like, they fall over and they bounce straight back up again. They shed a few tears because they enjoy the attention."
Less than a yard separated them now.
"You betrayed me."
The Doctor whipped out a hand to grasp the front of the Master's tunic, but the Master's arm scythed round to strike it away. He gripped the Doctor's wrist.
"No, Doctor, I disappointed you. There's a difference." With a bestial flash of teeth he struck the Doctor in the chest with both palms, sending him stumbling back against the wall. "I am not your assistant. I never will be."
The Master's eyes flicked downwards to the twitch of the Doctor's hand to his coat pocket. His smile hardened.
"Ah, yes, the remote control. You can turn me off, Doctor, and what will you do then? When you turn me back on in a week or a year or a century I'll be the same individual I am now, and you'll have gained nothing. Or you could leave me turned off forever, which means I'll be dead. You'll have murdered me. And I don't think you're ready for that." He took a step nearer, eyes fixed on the Doctor's gaunt, immobile face. "Not yet."
He watched the Doctor's hand flex and draw away from his pocket, and relaxed.
"So." He gave the Doctor a companionable clap on the shoulder. "Now that's all sorted out, why don't you come and see what I've been working on in the lab?"
He turned and walked unhurriedly from the room, and the Doctor sagged back defeatedly against the wall. For a few moments he just stood there, looking around with a stranger's eyes at the familar surroundings of his console room. He seemed lost, puzzled at what had happened to him. Then with an effort he roused himself, and with a sluggish, dragging step, followed the Master.
--------------------
Alison and Jenny waited an uneasy ten minutes until at last the Doctor's non-reappearance became too much to bear.
"Come on," said Alison. "He may need help. Or he may have forgotten to come back and tell us it's all over. Either way, let's go."
She retrieved her key and held it clutched tensely in her fist while they headed back to the Tardis. The doors were shut and the console room, when they cautiously poked their heads in, empty. They stood for a moment and heard the murmur of voices from along the corridor.
"They're talking?" said Jenny, puzzled. "I thought the Doctor was going to... I don't know, he said he was going to get rid of him."
"Oh, it's probably some wordy Time Lord showdown thing," said Alison dismissively. "I don't suppose he'll like it if we interrupt."
There was a pause while their eyes met, then with a mutual shrug they set off together down the corridor. They followed the sound all the way to the main lab, and stood open-mouthed in the doorway at what they saw.
The vampire lay flat on its back unconscious on the examination table. On either side, the Doctor and the Master adjusted equipment, checked readouts, discussed the results as if they were old colleagues having a normal day at the office.
"Doctor!"
He looked up at Alison's exclamation, saw them standing there and looked instantly furtive, like a shoplifter caught in the act. The Master ceased work, placed his hands behind his back, and watched.
"What are you doing?" she demanded. "You're working with this character now?"
"All right, Alison." The Doctor recovered himself and stood up straight, but the unsteadiness remained in his eyes. "Try and keep some perspective."
"Perspective?" repeated Alison furiously. "What the hell's perspective got to do with it? Have you forgotten what he did to Jenny?"
Jenny ducked her head, her hand lifting unconsciously to the wound in her neck. With a flash of anger the Doctor's voice sharpened.
"No, I haven't! And I've never made any secret of the things he's done in the past but that's never stopped you accepting his help before. In his twisted way he was trying to do the right thing. He used her to catch one of the creatures. More to the point, we're going to need his help again today if we're going to set things right around here."
"Right. Because he caused it. Or does he have an excuse for that as well?"
The Doctor blinked and looked down quickly.
"No," he said, his words indistinct. "We've covered that and I really don't want to go over it again just now. Perhaps we could leave it till we have a little more time to spare?"
"Leave it?" flared Alison. "I don't think so. After what's happened here maybe I don't feel like just assuming you know best. Tell me!"
"Ah." The Master raised a hand with a deferential air. "Perhaps, rather than force the Doctor to rake over old memories, I might field this one."
The Doctor eyed him bitterly, but turned away from the unashamed calm of the Master's gaze.
"Tell her, then." His expression fixed, he wouldn't look Alison in the face as he walked to the door and took Jenny clumsily by the arm. "Come on, Jenny. We'll find you a bandage."
The young maid acquiesced with her silence and the two of them departed down the corridor, leaving Alison, for her efforts, alone with the Master. With a self satisfied expression he settled back on his heels, re-linking his hands behind his back.
"So what are you looking so smug about?" she asked him scornfully. "Are you going to make out this is all his fault instead of yours?"
"Not exactly. But it's easy to see why the Doctor isn't comfortable with the story. It doesn't exactly redound to his credit."
She glared mistrustfully at him, standing there quite at ease with what he had done, assured of the power his secret held.
"Well, go on then, don't keep me in suspense. Tell me."
The Master told her.