oOo

Ace was standing with Harry near his desk, trying to look as if they hadn't been attempting to eavesdrop. The Doctor opened the door wider and gestured for them to join him. "Kyris has informed me that you two should hear what he has to say."

Harry and Ace filed past him, Ace's eyes glinting with curiosity and some other emotion. "You old dog, you," she murmured as she passed him, giving him a sly wink. Which meant, of course, that she'd bullied or wheedled Kyris' identity out of Harry. The guilty look his former traveling companion flashed him was all the confirmation the Doctor needed. He merely shook his head as he joined the others in Harry's examining room.

Ace had perched on the edge of the examination table, next to Kyris. Harry stood uncomfortably by the sink, fiddling with a tongue depressor and his stethoscope, while the Doctor took his former place by the door. "Ace, this is Kyris. My son. His mother was the lady we saw in Paris." He spoke as expressionlessly as possible, not looking at her as she nodded acknowledgment of the introduction. "Kyris has a few things to share with us now."

Which meant, of course, that he would brook no more delays. Ace and Harry recognized the tone, even if it was the first time Kyris had been subjected to it. From this parent, at least. The Doctor's pointed gaze was as unmistakable as his tone of voice, and Kyris shifted once, uncomfortably, before he started speaking. "The reason we came back to Earth was because of this." He held the half dollar-sized disk up to the light. Ace and Harry craned their necks to see.

"What is it?" Ace asked, flashing a glance at the Doctor. He seemed extremely interested in the answer to that question, while trying to appear as if he weren't. It was a particular trick of his, one she recognized and generally ignored.

"It's a mobile data retriever." At Ace's blank look, he added: "A search engine?"

"It's 1994, Kyris. The internet isn't that advanced yet," the Doctor put in.

"OK, call it a data filter, then," Kyris plowed ahead determinedly. "It's specifically designed to access information through the TARDIS database. From anywhere." The Doctor went very still at that, but Ace was concentrating on Kyris' explanation and didn't notice. "It filters and stores the information inside. It's still linked," he added glancing at the Doctor from under his eyelashes. Looking for a reaction. His father merely nodded for Kyris to continue. "One-way link, of course. Mother brought it with her to E-Space by accident. It was supposed to be a present or something; a way for you to look up your old companions and see what happened to them, where they were at any given time, without having to muck through the TARDIS files." He grimaced briefly. "Mother said they were a real mess."

"They still are," was the Doctor's only comment. But his mind was busy sorting through everything that innocent-looking piece of equipment represented. A dangerous toy, was his first thought; one he, personally, would never have attempted to create at his most whimsical--or ambitious. But Romana would have, and had, never thinking the consequences through, no doubt too caught up in the joy and challenge of pure research to bother about anything as mundane as potentially disastrous results. But consequences, the potential the tiny computer link represented, were all the Doctor could see, because the TARDIS databases were connected to the computers on Gallifrey. Still connected, even after decades of exile, countless years spent on foreign soil and under alien skies, and Romana not realizing or not knowing or even, he feared, not caring. She'd wanted to give him a gift, a pretty bauble whose dangers she'd not thought through when using her considerable genius to create it.

Enter the Master, the Doctor thought with a spasm of pain. He must have somehow discovered not only what she'd created, but had done what she'd neglected to do in extrapolating other possible uses for a portable, pocket-sized data filter linked through the Doctor's TARDIS to the computers on Gallifrey. Computers which were linked in turn to all the myriad worlds under Gallifreyan observation or influence or control, depending on where or when they happened to be in time and space. Computers whose information and literally millions of databases were constantly, ceaselessly updated and refined through those links.

Computers which, not incidentally, were the first link to the Matrix. And a link that allowed retrieval of one kind of data, no matter how specific, could be modified to retrieve other types of data--and send it as well.

The possibilities of what could be done through such a link both intrigued and appalled the Doctor. What in the name of the Great Unknown had possessed Romana to create such a thing? She had somehow managed to build a half-dollar sized bit of circuitry with the range to reach his ship across the void of time and space between this universe and E-Space, and the ability to function perfectly in spite of the distance and temporal differences inherent in the nature of the two universes. And somehow the Master had got wind of it and tried to take it for himself.

"So what happened next?" Ace was asking, bringing the Doctor back to the present. "Why'd you suddenly decide to come back here, all the way from E-Space?" Wherever that was, her tone implied.

"The Master," Kyris replied tightly, his eyes narrowing and darkening with hatred. "He found us, somehow, soon after Mother discovered that quite a lot of the Doctor's past traveling companions were dead. Not from old age or anything benign; they'd died under very strange circumstances, some looking accidental, but some definitely...murder."

Ace and Harry exclaimed aloud at that revelation, then both looked at the Doctor. His expression was grim, and his next question was spoken very softly. "Who?"

Kyris reached into his pocket and pulled out a crumpled piece of paper, hesitating only briefly before handing it to his father. "I wrote them down in case...well, in case."

"Jamie McCrimmon, Jo Grant-Jones, Tegan Jovanka, Melanie Bush," he read, raising disbelieving eyes to meet those of his son. "All of them murdered? It doesn't seem possible."

"Not Mel!" Ace protested, swallowing a sudden lump in her throat. The older woman had been the Doctor's traveling companion when Ace first met him, and had left almost immediately, before Ace had time for more than "how d'y'do" and "don't forget to write." But however brief, they'd shared an adventure together, and Ace had thought she would be great fun to get to know. That would never happen now, but she forced down the stab of grief as Kyris responded to their protests.

"Unfortunately, it's very possible," Kyris said flatly. "It's also obvious who did it."

"The Master." The Doctor's voice was as flat as that of his son; he didn't even look at the boy's nod of confirmation. "How?" was his next question. Not one Ace would have chosen to ask, but she could tell that the Doctor needed to hear it.

"Jamie McCrimmon was stabbed to death in his sleep in his home," Kyris began, struggling to keep his voice emotionless. "No trace of the killer or motive for the murder was ever discovered. Demons were seriously discussed when he was found, since the door was locked from inside and it was quite obvious he hadn't stabbed himself in the back after slitting his own throat." His voice remained even, but Ace could see how white he was around the lips. "The next victim was Jo Grant-Jones, killed in an apparent hit-and-run incident in broad daylight. That was in--"

"1980." This time it was Harry who interrupted. "The Brigadier, Lt. Benton and I attended the funeral," he explained, gazing in turn at the others. "She used to work for UNIT, a marvelous girl, very cheerful. You remember, Doctor." The Time Lord nodded soberly. He did, indeed, remember. "We were all shocked at her death, she was so young, but we never dreamed it was murder..." His voice trailed off in confusion.

"Witnesses said that the driver was a dark, bearded man in black who seemed to swerve the car deliberately to hit her," Kyris said, his voice turning grim. "And that he was laughing maniacally as he drove away. In spite of this, the police assumed--"

"--he was drunk," Harry finished, nodding his confirmation of the story. "It was ruled manslaughter, but the drunk driver was never caught. Dr. Jones--her husband--well, colleagues in the archaeological field said he was never the same after that."

The Doctor groped for the chair behind him, sitting heavily. "Tegan? Mel?" He was determined to hear the whole list, Ace realized with an internal shudder of sympathy. Every single one.

"Tegan Jovanka was killed in a plane crash over her parent's sheep ranch in Brisbane, Australia in 1990," Kyris continued. "She'd just gotten her pilot's license for single-engine aircraft. It was her third solo."

"That doesn't sound very suspicious," Ace objected. "New pilots crash all the time."

Kyris turned his gaze on her. "We thought so, too, until we saw that the police investigation turned up evidence that something hit her, collided with her in mid-air. And they never recovered a body." Ace bit her lip and flashed a glance at the Doctor. Who continued to listen impassively. "There was some flurry about UFOs, and that was it. Another flamboyant, ambiguous death."

"Keep going," the Doctor said stiffly, and Ace shook her head in admiration. He was as stubborn as they came, that one; he was obviously hating every word of this, but was equally obviously determined to hear it out. All of it, all the details, not just who and when. No, he had to know the how of it as well, and Ace couldn't tell if he thought it was the least he owed his former traveling companions, or whether it was a form of penance for allowing it to happen to them. Nor was she certain she wanted to get that involved in the Doctor's thought processes; he'd always kept his private feelings private, no matter how much he'd opened up to her about Susan...had it really only been a few weeks ago? It felt much longer, and Kyris' death list wasn't helping. She repressed a superstitious shudder, forced herself to concentrate on his words instead.

"Mel's death was much simpler," Kyris was saying. No one missed the ironic note in his voice. "She died of snakebite two years after Tegan's death." He paused. "Of course, since she was taking down a computer system at a closed military base in Antarctica at the time, it was a rather suspicious snake bite."

Ace felt the prickle of tears behind her eyes, and sternly forced them down. Public displays weren't her style, and she'd much rather mourn her almost-friend in the privacy of her own cabin. Besides, like the Doctor, she wanted to hear it all, and now she didn't care if it was atonement or a simple need to know the facts; motive wasn't important.

"No one was implicated or arrested, not even the members of her team. None of them had the motive or the actual opportunity," Kyris continued. "It was as if someone appeared, released the snake--they found the body, King Cobra, dead of the cold soon after it bit her--and vanished without a trace. Whoever it was picked a time when Mel was alone outside the base. Her team members were all together in the camp, within sight of each other the entire time, none had a grudge or even a disliking for her, and the investigators couldn't believe it had been a conspiracy of the ten of them against her. There just wasn't any evidence to lead to such a conclusion."

It was the Doctor's turn to take a deep, shuddering breath. "At least she made it back home," he said softly.

"There's more," Kyris said after a moment's uncomfortable silence. "Mother figured out that the Master was making the deaths so flamboyant because he wanted you to know it wasn't coincidence, that they were all being murdered for a reason. One companion for each regeneration, you see. All but the fourth and the first. We figured that he was after one particular person for each, and Mother, she thought that she--" He stopped, unable to continue, and his father quickly spoke the words his son couldn't quite manage.

"She thought that she was for the fourth."

Kyris nodded, then continued in a ragged voice. "She also figured out who he was after for the first. Someone named Susan. Susan Foreman." He studied the Doctor with clinical interest, waiting for his reaction.

"Campbell," his father corrected him absently. "Young David's last name was Campbell, and she took it when they were married." He shook himself and looked first at Kyris, then at Ace. "Well, Ace, it looks as if this mystery and the question of my missing memories regarding Susan are very much connected."

"The Master doesn't know that her name is Campbell; he doesn't even know when or where or who she is. It's one of the reasons he needs this," Kyris broke in excitedly, holding up the small disk. His resentment toward his father seemed to fade somewhat as he concentrated on putting together the facts. Very like the Doctor, Ace couldn't help thinking, to put aside personal feeling when "on the case," so to speak. "He can't tap into the TARDIS computers directly, and without that information, he can't find out who Susan is, where she is, or anything else about her. He could randomly search through time and space, but he doesn't know where to begin; he doesn't even have a timeframe to start him out."

"And his TARDIS' connection with the computers on Gallifrey was severed quite a long time ago," the Doctor added grimly. "It hasn't seemed to matter to him. Until he somehow found out about this, had an immediate need for it as well as an ability to see the long-term usefulness of such a device."

"And it's even harder for him since Susan's not from Earth," Ace interjected excitedly. The Doctor shot her a look, but refrained from comment. Ace was puzzled; even if Harry didn't know who Susan was, what difference would it make? Then she understood. Her eyes widened in alarm and she opened her mouth to rush out an apology, but Harry was already speaking.

"I'm sorry, who is Susan?" The puzzled expression on Harry's face deepened as the other three exchanged glances. "Am I missing something here?"

"Yes, and I think we'd best keep it that way," was the Doctor's clipped response. "I'm sorry, Harry, I don't mean to keep secrets, but if the Master is after Susan, it would be very dangerous for you to know any more about her. We probably shouldn't have even let you know her married name, or even the fact that she is married. Anyone who knew her, knew about her, could be in danger. In fact..." his voice trailed off as an expression of fear flashed across his face.

"What is it?" Harry asked, tensing.

"I think we'd better be going now," the Doctor said, ignoring Harry's question. He rose to his feet. "We could be endangering you by our mere presence. Kyris--" he hesitated, not quite certain what to say. "If you wouldn't mind coming with us--"

"You're who I was supposed to look for," Kyris responded with a shrug. He came to his feet as Ace hopped down from the examining table to join them at the door. "Thank you for all your help, Dr. Sullivan," he said formally. "I hope to see you again."

Harry smiled faintly. "As do I. I hope to see all of you again. And soon." He shook Kyris' hand, then Ace's, then turned to face the Doctor. "Keep them safe."

The Time Lord nodded. "As safe as I can," he promised. "As safe as I can."

Harry watched them file out the door of his examining room and into the TARDIS, one by one, the Doctor the last to go. He hesitated on the threshold, turned, and raised his hand in a brief salute. Harry waved in return, watching stoically as the TARDIS vanished.