My thanks to Steven A. Henry, MD, for his technical advice on this story.
The gentle throbbing of the TARDIS interior gave Sarah Jane an eerie sense of another presence. All systems were normal and at rest. But without the Doctor inside, the control room seemed even larger and more vast than it had the first time she'd ducked inside and hidden herself away.
She found herself unwilling to cross the great, gleaming floor to get to the door that led into the back. A sense of being exposed and vulnerable assailed her, even though she knew that she was alone and undetected in the great, transcendent time machine. At last she made herself step forward. Just as she did, an air compressor let out a click and a great sigh, and her heart jumped. She was trembling. When she stepped forward again, the lights brightened. She resisted the urge to run out again. But she did look back to make sure that the doors were open just a crack. She did not want to be trapped inside. After only two forbidden steps, the TARDIS was quite an oppressive, unwelcoming place.
But she forced herself, a step at a time, across the great control room. Beyond this, she knew, were the Doctor's work rooms and labs, and beyond them, guest rooms and wardrobes. She did not know what secrets lay beyond the guest rooms. She decided that she would simply take a peek at the labs, confirm that they were empty, and then go back outside and get to the job she had come to do: examining the files. Atkins would be gone by then.
The first two labs were desolate. Bits of equipment lay scattered around each of them, as though these rooms had not been used in some time. She should have felt more assured, but instead she felt unease growing on her. The entire place had a sense of too much space and too much silence. She felt that she was being watched.
Just one more, she thought, and then I'm out of here. But she no longer liked the TARDIS. She was amazed that she had ever willingly traveled in it. It was a brooding and alien place, and now through it she sensed how very alien the Doctor was. He could be anything; he could do anything. All the rest about tea and a roadster and opera were just window dressing. He was very alien.
She found another door. She pushed it open and peered inside. This room remained dim, even when she poked her head across the threshold. It was not perfectly dark, and it emitted different rhythmic noises than the other rooms. She carefully entered.
Across the room, there was what looked like a blast wall, with a reinforced glass panel in it, so that somebody could duck behind it and still see out into the room. Far more alarming was what lay in the center of the room, in direct view of the observation panel in the blast wall.
A stretcher had been set up, and on it lay a young woman. There were flexible cords running from her to the blast wall, and a sophisticated ventilation machine, its front panel checkered with digital meters for reading information was at her head. Its tube snaked into her mouth, which had been forced open as far as it would go. Her jaws were impossibly far apart, and were frozen in place as though in a silent scream. The sound in the room was of her breathing. The machine magnified it.
Only then did Sarah Jane realize that the blast wall was shielding a dimly lit operator's station, where a person could stand and direct something from cover.
This room, of course, changed everything. Several possibilities, all of them dreadful, rushed into Sarah Jane's mind. The crucial issue was whether or not the woman on the stretcher was alive, and if she could be taken out of this place.
Sarah Jane crept forward. She did not see a white suited figure behind the blast wall suddenly step into view of the reinforced glass and quickly look at her in surprise. This figure quickly ducked out of sight again.
"Can you hear me?" Sarah Jane said quietly before she reached the stretcher. "Miss, can you hear me?" She made herself come right up to the stretcher and ventilator, and she looked down at the young woman.
There were electrodes fixed at the woman's temples, and more wires ran under the thin blanket that covered her, indicating that electrodes had been fixed all over her body. The wide ventilation tube was crammed into her mouth, and a thin tube of clear liquid also ran from the sophisticated life support machine and snaked along the top of the blanket, disappearing into the girl's wrist.
She seemed not really to be alive, or at least not able to be alive apart from this dreadful machine. The idea that she was being kept alive struck Sarah Jane most forcibly---that her life had been stripped off of her and then forced back into her only a very little at a time.
Sarah Jane looked up just in time to see an angular, robotic figure slip out from behind the blast wall. For a moment her eyes could not define what she was seeing, and then she realized that it was a person dressed in a white protective suit such as might be worn for an extremely radioactive area. The head was encased in a non-conductive globe with a metallic finish, and air hoses ran from a light weight tank in the back up into the sides of the mask.
It was a horrifying sight to see.
"Get back!" Sarah Jane exclaimed, and she skittered back. "What are you doing to that girl? Who are you?"
A voice behind her suddenly exploded into angry speech. "What the devil are you doing here?"
It was the Doctor.
Sarah whirled to face him, and then backed away from the both of them.
"What is that?" she asked of the white clad figure. "What are you doing to that girl?"
"Trying to save her life!" the Doctor snapped. "How did you get in here?"
"I---I walked in. I just came in."
"I told you I would be at the opera tonight!" His eyes were angry and indignant. The white suited figure, its face hidden by the helmet, tapped its own wrist, a signal that time was passing.
"Get behind that wall!" he exclaimed at Sarah Jane. "Right now!"
She was frightened, but she made herself speak clearly. "I w-want to know what you're doing to that girl!"
"That young woman has been invaded by a single parasite that we have not been able to shake loose from her. She's been in stasis for three years, and we have finally figured out a way to bring her back by expelling him. This is a very dangerous place for you to be!"
The figure in white tapped its wrist again, more urgently.
"Yes, all right. You!" And he caught hold of Sarah Jane's arm. "Get back behind that wall, and don't touch anything. Stay well away from the controls. All right, you see to her," he said to the helmeted figure, and he gave a nod to the woman on the stretcher. Sarah Jane found herself moving behind the blast wall with him.
"And stay there!' the Doctor exclaimed. He back strode to the ventilator. "Get ready for a whopping attack of anything he can throw," he said to his masked companion. "You've locked on the frequencies?"
It nodded. It took a position at the girl's chest and set down a small array of capped syringes. The Doctor adjusted the air flow. He appeared to be increasing the rate of ventilation.
"Are you ready with that calcium?" he asked, and the white suited attendant nodded. It tapped a flat iron plate that lay alongside the girl's body, which even Sarah Jane could recognize as a defibrillator, to restore heart action. The Doctor strode behind the blast wall, ignoring Sarah Jane Smith. He operated several controls and kept his eyes fixed on a small oscilloscope screen set into the panel. "I'm elongating the cycle now, pulling out the sine wave."
The other person spoke, but her voice could travel only from a microphone inside her suit to a small speaker grill on his panel. It was a woman's voice, cool and observant. "The nervous system is agitated. Blood is acidifying."
"What are you doing to her?" Sarah Jane whispered.
"We are bombarding her nervous system with an extremely low voltage, long wave transmission. We may be able to knock the insider out of her. But he's going to play a game of chicken with us, sending her body as close to death as he can get her, so close that he thinks we'll back off from fear of killing her."
"You've been doing this to her for three years?" she gasped.
"No," His voice was calm, his eyes steady as he watched the long, almost level line that slowly traversed his screen. "We've had her stabilized in what you would call suspended animation. Neither Professor Shaw nor I were ready to do this until now. We had to come to a better understanding of the effect that sine wave harmonics would have on her nervous system as well as on the invader inside her."
Sarah Jane could not resist the most urgent question on her mind. "Did you do this to her?"
"What, infest her?" For one moment he darted an angry glance of resentment at her before staring at the output screen. "I thought you knew me better than that. She's suffering."
"Her heart is flat lining, Doctor!" the voice over the speaker said.
"That's from the blood acidity. Give her the calcium!"
"I've got it." The figure, discernible through the reinforced glass, expertly set a syringe directly into the chest of the prone young woman, alongside the sternum, and with a practiced, smooth strength, depressed the plunger.
"You've got to try an electrical contraction," the voice said. "She's not oxygenating properly. He's taking her!"
"Stay calm," the Doctor said steadily. He activated more controls. "I told you he would tax our nerves. You've got to trust me on this, Liz. I've tried an electric contraction. Did you read it?"
The figure in the helmet glanced at some LEDs on the ventilator. It nodded, and the voice said, "Yes. But she's not going it on her own. The heart is still moving towards a flat line."
"Steady on," he said calmly. "There's heart activity. I can see it on the panel. Here's another."
"I'm giving another two cc's," the voice said as the figure used the syringe again. "I'm ready to start heart massage. Her brain activity is declining."
Sarah Jane's voice interrupted their tense concentration. "That girl's going to die!"
"Something's going to die," he said. "It couldn't be helped. He wouldn't compromise with us" His voice suddenly became alarmed. "Liz, the signal is just now creating harmonics. Something's creating an inductance in the machine!"
"It's him! He's using his own slight mass to effect the electrodes!" the voice exclaimed. "Can you rectify it?" The woman's voice, slightly mechanized by being transmitted, caught itself. "Wait, her life signs just jumped up. She's coming back to us. She's gagging on the tube---"
"Signal harmonics are jumping. The signal's voltage has increased. What's he doing?" the Doctor exclaimed. "He's taken over the signal!"
The limp figure on the stretcher suddenly came to life. It lifted its hands and jerked at the tube that had been forced into its mouth. The white suited figure quickly grabbed the young woman's hands to stop her. Sarah Jane, amazed at this sight, rested a hand on the control panel and peered through the glass.
"Sarah Jane, get back!" the Doctor shouted. But just as suddenly the control panel erupted into several white and blue arcs. A tremendous shock threw Sarah Jane back against the wall. Something burning hot and black seared a path up her arm and into her heart and spine. She heard a voice scream, "Not again or I'll kill her, Doctor! Something's got to make due! She should have died!"
That's my voice, she thought, and then a hot, electrical fire tore through her. The Doctor's voice was terrible, and for a moment she thought he was angry with her, and that he was going to rip her apart. She had no means to orient herself. She had lost the conscious use of her legs, but she didn't know if she were standing, or somehow hanging as though from a hook, or lying on the ground. And then the Doctor's eyes were going into hers, looking for her as though she were at the end of a tunnel. Her heart gave a great leap and then constricted as though a hand had seized it and crushed it. She couldn't breathe.
"You have the succinylcholine?" he asked. "Give it here."
The white suited figure would not come into focus. Sarah Jane felt the constriction on her heart increase, and she sensed an anger and a desperation of something that was resting alongside her heart. It was angry with the Doctor. And then the Doctor's voice was articulate to her. He had been talking ever since the electricity had arced into her.
"This is going to quiet your limbs, Sarah Jane," he said. "It will quiet your nervous system."
"It gives us only about two minutes Doctor," a clear, urgent voice said, the woman's voice, now free of the helmet. "He's learned how to combat it. He'll be smarter with this one."
"He's already proved that," the Doctor said ruefully.
"Do we intubate and try the same thing again?"
"No, he's figured out how to harmonize the sine wave. That one's alive?"
"Yes."
"Keep her sedated. Get this one intubated." The Doctor looked down at Sarah Jane. She realized that he had carried her to the stretcher. Her limbs, as he'd said, were now useless. But the constriction on her heart had slackened to a more bearable level.
"This is Professor Liz Shaw," he said. "She's going to look out for you while I take this other young woman to a safe place. I'll be right back."
And then his face whisked from view. It was replaced by the professional, concerned, but somewhat detached eyes of a woman, hardly older than Sarah Jane herself, whose face was shining from having been encased in the helmet and breathing apparatus. She had reddish hair. She did a quick survey of Sarah Jane's face, and then she said in a very professional voice, "This is a sedative. You have nothing to be afraid of. We've got to make sure that you keep breathing. You'll be able to hear us, and we'll keep talking to you." A sedative, she realized, meant they were going to put the tube down her throat.
There was a distant sting from somewhere on her paralyzed body, and she felt the constriction around her heart try to tighten, as though in protest. The woman had said only two minutes. Two minutes until what?
There's something inside me, Sarah Jane thought. She tried to say it, but the two drugs prevented her from speaking. She only managed a small moan. The woman rested a hand over her forehead. "We'll get you out of this," she said calmly. "The Doctor is here."
"Clear the room, Liz," his voice said. "The electronics won't work in time. Not now. He has a better idea of what to do. Clear the room. I'm going to try something else. A light ray that will kill off the components of her immune system. The macrophagic activity will cease. The light wave disturbance will drive him out."
"Doctor---"
"We're running out of time!" he snapped. "Do it and go! There's less than a minute left before he gets himself completely entrenched!"
"Cover her eyes," the woman said, all business, and he rested his big hand over Sarah Jane's eyes, covering her with a darkness. "Don't be afraid, Sarah Jane. This will be over in a minute. I'm staying with you."
The sedative's effect had been growing, and she didn't struggle against the tube. His other hand grasped her hand, and the job was finished quickly. "Go on," he said to Liz Shaw. "Throw the emergency controls and get out. Wait for us." And then, as two tears trickled from Sarah's eyes, his voice, much more kind and calm, was all around her. "I won't let harm come to you, Sarah Jane. I know you're frightened, but it's going to be all right. I'm going to force him to come into me." He lifted his hand from her eyes and stroked her head. "Let it put you to sleep. I have you, and I'll help you."
There followed a sudden warmth and a sharp cramp in the very pit of her stomach, and then she felt her lungs lose their effectiveness. Before it could really frighten her, she drifted away on a sea of dark confusion.
From very far away, she heard a great yell, from a man. And then quick and light footsteps, and a dreadful voice, Liz Shaw's voice, exclaiming, "Doctor, what have you done?" But the constriction had left her heart, and that residue of a burning sensation was gone from her arm and spine. She felt somehow freed. But she couldn't bring herself back to complete consciousness. She heard somebody furiously working, and then the Doctor's voice, weak and not loud enough to catch the words.
When she came back, she first saw the woman. Liz Shaw, her eyes still intent, concerned, and detached. She was wearing the white protective suit, but a more conventional surgeon's mask was down around her collar, hanging by its strings. She was also wearing a stethoscope 'round her neck.
"I'll have to complete some mildly uncomfortable procedures," she said to Sarah Jane. "The Doctor has medications to restore what we destroyed in your immune system, and I've added some to your air intake, but the others must also be directly applied. I'll make you comfortable first."
Sarah wanted to ask if he was all right, but she still could not form words. She felt another slight sting, and then she became very woozy indeed. She stopped being afraid at all, and she stopped feeling any regrets, and she stopped knowing where she was. She felt a furious pushing, and it began to annoy her, because she would have liked to drift off to sleep. Her entire body was being rocked, hard, from hips to neck, and then suddenly she felt an enormous stomach cramp. In spite of the anaesthetic, she nearly doubled over in sudden agony.
"All right, all right," she heard the woman say. "That's how it should be." And something warm and heavy was pressed to her abdomen to ease the cramping. "It's working, Doctor."
And then the woman, her surgeon's mask now in place, stepped up to Sarah Jane's head, covered her eyes with her hand, and before Sarah could fear anything, the tube was smoothly extricated from her throat. Her jaws were sore.
The woman put the stethoscope prongs into her ears. She applied the sensor to Sarah's chest and listened. "Yes, respiration is being conducted normally. The oxygen exchange is restored. Doctor, you're sure you're all right?" And the calm intelligent eyes flicked across the room. Sarah Jane followed the glance. The Doctor sat on the floor against the wall, as a man would do if he were exhausted after a great fight. Scorch marks were burned into the flooring around him.
"My heart almost stopped when I realized you'd taken hold of those power cables. You might have killed yourself," Liz Shaw said. She removed the stethoscope prongs from her ears. Then she hooked her index finger over the mask and pulled it down.
"I killed the Insider anyway," the Doctor said quietly. "Burned my hands and feet. But it worked."
"You're certain that thing is dead?" Her voice was concerned.
He nodded at the scorching on the floor. "I told you that it has some slight amount of mass, slightly more mass than you would find in photon packets. That's the evidence of it. You might say that those burns are the evidences of his mass being converted to energy. He came into me when he thought he couldn't use Sarah's body, when the macrophages and spirochetes were destroyed. And then he tried to escape from me when I sent that power jolting through me. But the arcing caught him. He's dead."
"And yet he traveled into this woman by means of an electrical charge," Liz said. "Why didn't the charge kill him then?"
"He entered Sarah Jane by means of a controlled electrical charge," the Doctor added wearily. "A low voltage charge that he was able to increase. But he couldn't withstand several hundred volts coming at him at several amperes. It burned him up. Almost burned me up, too. But everything's all right." His voice was weary, but satisfied.
Sarah lifted her head. She was regaining a sense of shame from what she had done.
"You're all right," the woman named Liz Shaw said instantly. She brought a cup of water to Sarah Jane and lifted Sarah's head on her own arm to help her drink. But in spite of her kindness, her voice was stern. "Though you don't deserve to be. You endangered that other young woman, and you endangered the Doctor, not to mention endangering yourself. You don't belong here."
"Oh, she's very young, Liz. She didn't know. She was looking for me," the Doctor said.
This lenient reply apparently startled the woman doctor very much. She glanced over at him, puzzled. Sarah Jane was grateful to him.
"Please tell me---what happened?" Sarah whispered.
"We cannot tell you that," Liz Shaw said. Her voice was neither friendly nor unfriendly, merely detached. She set aside the cup and carefully applied a soft cloth to Sarah's bruised lips and mouth.
"Liz." The Doctor's voice was mild, and not just because he was weak. With a great effort, he got to his feet.
"Doctor!" Liz said reprovingly. "You shouldn't stand up---"
"No, no." He managed to stand, and he walked shakily to Sarah Jane's side. He rested his big hand on her forehead. "There was a wandering sort of parasite, Sarah Jane. A creature of very low mass who does very well manipulating micro-voltage cellular operations. These creatures prefer to find a host newly dead to inhabit and control. They make use of people who die of suffocation or drug overdose, victims who have a fairly healthy system that they can take over and rejuvenate for a few months. It's a matter of good timing, as they have to catch their prey just dead to take over successfully."
He stroked her hair. "They are unpleasant, of course, and I know that humans dislike the idea of body snatching, but they never have been aggressive that I've heard of. But this one apparently went into a drug overdose victim who came back from a death-like state. He was having a go at either driving her out or controlling her. We had to keep her in stasis until we could figure out how to get rid of him without killing her. I'm afraid that in thirty six months, even with the controls we had over him in here, he still figured out far more about how to inhabit a living person than I would like."
"It's an intelligent parasite?" she whispered. "Not just an insect sort of thing or a germ?"
He nodded. "Very intelligent. But as a matter of fact, his species can overtake the bodies of insects very well. Ideally, in fact, for the electrical signaling of the chemical reactions in insects is quite suited to them, but insects give them only a limited reality to work with. Intelligent, rational hosts are better. They can reactivate the brain activity of their hosts to interact with the physical environment on a sensory level. So the more sophisticated the brain, the better they like it."
Liz Shaw spoke up. "We'd finally figured out a way to counter act its signaling, which is its means for staying in a body and controlling it. We needed a perfectly pure signal of our own at a perfectly tuned long wave frequency. But it's so smart that it began to degrade our signal, causing harmonics. That gave it enough time to sense you and run itself through the wires to the panel and give you a strong shock----"
"And while your system was paralyzed by the shock, it entered you," the Doctor added. "But we made you a rather unpleasant host for it by destroying the microscopic creatures that you depend on for oxygen exchange and other biological processes. Then it went into me, for my system is sophisticated enough to house one of these creatures and keep it in stasis, provided I let it in---"
"You let it in? And you killed it?" Sarah Jane whispered.
His eyes were grim. "I had to. It had gone from being a scavenging creature who takes advantage of death, to being an aggressive predator who causes death. It would have killed her, and it would have killed you, to make itself a nice home. The change occurred when it learned that it could take over a living person's nervous system, provided it got a strong foot hold." He took her hand, asking for her understanding. "I couldn't keep it captive indefinitely, and I couldn't protect other human beings from it."
"And you're sure you're all right?" Liz Shaw asked him.
"Yes, quite. Just tired. But it is time now for us to inform the Brigadier. This ought to go into the official record."
She turned disapproving eyes to Sarah Jane. "Why did you come here? What were you looking for? You had no right to enter the lab, or this TARDIS."
"I was looking for the Doctor," Sarah Jane said meekly. She knew she had behaved badly. The first time she'd sneaked into the TARDIS, it had been a bit of a lark, but this was the betrayal of a friend. And the Doctor had run a great risk to save her. She was quite ashamed of herself.
He came through for her now. He stroked her forehead. "Sarah Jane is a great friend of mine," he said gently. "She didn't understand, Liz."
Liz nearly retorted, for she knew full well that he had invented a cover story of going to the opera so that she and he could work on their project secretly. This Sarah Jane, whoever she was, had deliberately sneaked into his TARDIS. But as she fixed her eyes on him and saw him gently smoothing aside the bangs of this frightened young girl, she did not answer him. He had mellowed; he was gentle with this child. Liz decided not to chide him for this, but it surprised her. He had been harsh, imperious, and quick tempered during her tenure. Who had mellowed him?
She forced herself to speak more civilly to the girl, though she still felt the danger that this flighty young intruder had caused. It had been a near thing. "Very well, then," and she softened her voice. "You'll have to stay right here for at least several hours. Your immune system was completely destroyed, and we've been able to restore its foundations, but it needs a bit of time." Her voice suddenly sharpened. "Doctor? Your hands are shaking. What's wrong?"
He lifted his hands quickly. Sarah Jane could see that they were trembling visibly, as though from a palsy.
"Must be an after effect of that great electrical shock," he said. He frowned at his hands. "There, I've stopped it."
"No you haven't!" Liz was concerned.
"Well, I almost have. Look, you've got to see to the other young lady. She's been in stasis for three years. You've got to look after her, Liz. Explain it to the Brigadier, will you? I've got to see to Sarah Jane. I don't want to leave her alone."
"You'll have to help me. You'll have to carry that girl out of here," Liz said.
"Right. Go see to her, will you? I'll be right along. I want to make sure that Sarah is comfortable."
He was picking up the discarded syringes that had been set aside during the rapid rescue of Sarah Jane. Liz nodded and then stopped. "Do be careful, Doctor. One of them has succinylcholine in it. If you jab yourself with it, you'll paralyze yourself---or worse."
"Right, here it is. I'll be careful." His voice was cheerful.
Liz hurried out. The Doctor turned to Sarah Jane. His hands were still trembling. "That's him," he said to her. "Trying to get control again." He examined the syringe and quickly fixed the point against Sarah Jane's arm, in spite of the tremor in his hands. "I've taken him by surprise, just like I'm taking you by surprise." And he deftly injected her. She tried to get up, but in spite of the trembling, his hand was strong. He set it against her shoulder and pushed her back down. He held her in place on the stretcher. In a moment, she couldn't move at all.
"We're going to my home, Sarah Jane, where I have many lovely companions. They'll all want to meet you, especially once I've taught them how to take over a living body. It's not so difficult."
"Doctor?" Liz's voice called.
"Coming!" he called back. He sounded just like the Doctor. He leaned over her. "And I'm going to pick one, just for you, and we'll come back here with a host of our friends."
She couldn't speak. The paralysis was too complete, but he explained himself. "A man's got to start a family. Create human children to host my people. At the start. And then develop better ways to take them over." He rested his finger on the tip of her nose, a gesture of playful gentleness. "Don't go away. I'll be right back, and then we'll be on our way."