"I suppose you'll be wanting your equipment back," said the Doctor.
"No, not at all. Consider it a gift. I would, however, like the artefact returned."
Somewhere in the building an alarm sounded, and Leto heard booted feet running overhead.
"Looks like you're a bit short on time."
The Master smiled, stepped into the room and shut the door. "No, I don't think so. I have three hostages. I very much doubt the Brigadier will wish to charge in, guns blazing. Right, now if you would be so kind as to give me the artefact, Miss Grant."
"So what's it for then?" asked the Doctor.
"You don't recognise it?" The Master took the artefact carefully from Jo's hands, quickly pocketing it.
"Well, it is camouflaged."
"You always did lack skill in the practical application of science, my dear Doctor."
"If it's still mimicking the Roman remains, then I'd say you haven't had any success either."
Leto barely listened to the argument, the exchange of barbs was clearly a familiar pattern to both parties. The Master had the artefact, he should leave, now, before he was discovered, but this Doctor did something to him. She remembered how efficient, how ruthless, how well-planned every step had been when he began to research a cure on her homeworld, but now he was being so easily distracted by the Doctor. It must be what the Doctor wanted, of course, to give the soldiers enough time to locate their escaped prisoner, prevent him from leaving the building.
She looked round the room. More than one exit, and she doubted the windows were secure. There was even an open corridor to her left; an open corridor and, yes, there was someone there. She moved back against the wall, slipping into a chair and trying to appear as innocuous as possible. It didn't matter, both the Doctor and Master were far too concerned with exchanging insults.
"Well, Doctor, I think it is time we were leaving."
The soldier moved into the laboratory, not quite far enough, and levelled his gun at the Master. "Not so fast, mate. You make one move and I'll put a bullet in the back of your head."
The Doctor smiled, satisfied, and the Master slowly put up his hands. "Ever punctual, Sergeant Benton," he said.
"Right, now turn around. Slowly."
The Master did as he was told, watched the Sergeant with a level gaze. He did not so much as glance at Leto.
Either the Doctor had Jo had forgotten she was there, or they had dismissed her as a threat. They said nothing as Benton stepped into the room.
It was far enough. Leto swept off the chair and gave a swift punch to the Sergeant's neck. She wasn't particularly strong, but she knew where to hit, and it seemed that human physiology was close enough to her own for the punch to still be effective.
As he fell to the floor, the Master turned back to the Doctor and Jo, once more levelling the revolver at them. Leto picked up the sergeant's gun, then grabbed some wiring from the workbench, quickly tying him up.
"Let's go," snapped the Master. As they left the lab, he kept the gun pressed against Jo's back.
When they got outside, the Doctor called for the soldiers to stay back, and they made their way towards his strange yellow car.
Just once, he caught her eye, and she saw the disappointment and dismay in his face.
- - -
They were back at the house. Undoubtedly UNIT had followed, at a distance, and it was only a matter of time before the Brigadier attempted to retrieve the hostages. There was still equipment here, carefully hidden and untouched by UNIT.
The Master glanced up as Leto descended the steps into the cellar. "They're secure," she said. "And I would very much like to know why we are still on this planet."
"Was that a demand?" He was irritated by her tone of voice, by her presumption.
"It isn't safe; it isn't secure. Why do you stay here?" she asked.
He sighed, decided to answer. There was, after all, no reason not to tell her and for the moment he was satisfied that her allegiance to him was secure.
"Because there is a time-space lock on the artefact. Its creator was well aware of who might seek it out and wanted to make sure it did not fall into the hands of those too primitive to comprehend its power. If it enters the vortex still in this state it will be useless."
"But in the capital…"
He interrupted her. "That piece had quite a different method of keeping its secrets. Now, please, I must concentrate. Keep a watch on those two upstairs and if anything turns up on the scanner let me know at once."
- - -
Leto brought a cup of water from the kitchen to the hall where Jo and the Doctor were cuffed to the radiator. "I thought you might be thirsty."
"Thank you," said Jo, and Leto put the cup to her lips, tipping it gently so she could sip at it. Her bound hands did not give her enough freedom of movement to do it herself. When she had had had enough Jo nodded and Leto turned to the Doctor but he shook his head.
She turned to go, but the Doctor spoke. "Leto, why are you helping the Master?"
Her grip tightened on the cup, and she wished that she had just kept walking. But something about the Doctor's tone made her want to answer. She looked at him, but saw no accusation in his eyes, just a mild curiosity.
"If he had not taken me from my world, I would have died. My obedience is the price of my life." She walked towards him, crouched down so that her face was level with his. "You thought he was controlling me, but no, I know what he is, what he is capable of and I made my choice."
"You don't owe him anything," said the Doctor quietly. "He destroyed your world."
Leto shook her head. "He provided a catalyst, perhaps, but the seeds of destruction had been long planted. We accepted his help willingly, he cannot be held to account for what we chose to do with that knowledge."
"And what did you do?"
She gave a tight smile. "He agreed to work on a cure for a plague that had infected my world. As proof of faith, he gave us something quite different; weapons far more destructive, more precise than anything we had yet created. But one particularly ambitious family decided to make free use of that knowledge. In their haste for power they bombed a hospital." She paused, her eyes flicking away, steeling herself to finish. "It wasn't just a hospital. It was a bio weapons research plant. We created our own plague, Doctor, and then we let it loose."
"I'm sorry."
"I don't want your pity."
"I'm not offering you pity. I'm offering to help you. You've suffered, you're hurt and I don't believe that this is what you want to do."
She stared at him, her face tight with anger. "Don't presume to tell me want I want, Doctor."
"The Master is using you."
"I know that."
He leaned towards her, as close as he could, looking into her eyes. "Leto, don't you want your freedom?"
She stood up and stepped away from him. "To be honest, Doctor, I wouldn't know what to do with it."
The low buzz of an alarm distracted her from anything else the Doctor would have said. She ran to the kitchen, glanced out the window, but saw nothing incongruous and then turned to the scanner. UNIT were arriving and in no small numbers.
And then there was an explosion in the hall.
Leto flung herself to the floor, but there was no sound, no crumbling masonry falling around her. She realised that it hadn't been an explosion at all but a tremendous release of light: bright, white and enough to blind her for a few seconds.
She dashed out of the kitchen, past the Doctor and Jo - still disorientated - and down the stairs to the cellar.
The Master was there, a triumphant expression on his face. He turned to her, holding what she assumed to be the artefact. It was beautiful now: like glass holding liquid light, colours swam through it and for an instant she thought she could make out symbols pressing against the surface, struggling to escape.
The Master noticed her then. "Success, Leto. Time for us to leave this wretched little world."
She was still staring at the artefact, she had barely heard him but then she remembered, "UNIT are on their way."
He nodded. "Right then, time for the Doctor to make himself useful."