Some impulse prompted him to check on Ace. Intellectually he knew she was fine; they were on the TARDIS, she'd gone to the console room to harangue the Doctor, nothing could go wrong... But something, some instinct, propelled his motions. He punched in Ace's name. Pressed a final button (so archaic, this TARDIS, to still have buttons and levers). Waited. Scanned the results.

Paled. Looked again. Whitened further.

Turned and headed for the console room at a steady, ground-eating pace. Not panicked, no; not running, not skidding down the corridors, careening off the walls, breathing heavily. Just...walking. Quickly. No hint of his emotions on his face now, only determination. Even his color had returned. He knew anyone looking at him would think he was in a hurry, but nothing else would give him away. That was how he needed it to be, when he caught up with them. If they were still in the console room, as he hoped they weren't.

"You made it so it crossed the time streams, Mother, it shouldn't work that way," he might have been heard to mutter to himself as he walked. "I shouldn't have been able to see her future, not now. Never mind access to the matrix, that capability alone makes this the most dangerous toy you've ever tinkered together. What were you thinking?" He raised his voice, briefly, in frustration, noted with surprise that his fists were clenched, his teeth grinding. So much for not letting anyone know he was upset. Hard to keep that secret anyway, not from the TARDIS and through her, his father.

He paused, hesitating, uncertain, as he realized he'd left the disk in the reader. Should he go back and remove it, take it with him? No, too dangerous; he couldn't have it with him when...well, when. He'd just have to risk the Doctor figuring out what he'd seen, and hope his father had the sense to keep it from Ace. "So much for the future," he whispered bitterly as he started walking again, face resolutely set, mind deliberately focused, emotions pushed aside or down or whichever direction emotions went when the mind purposefully needed them out of the way. He couldn't stop the TARDIS being aware of him, but he could dampen his emotional broadcast.

He had to stop it. Never mind the laws he was breaking, would be breaking; he wasn't an official citizen of Gallifrey and certainly hadn't graduated from the Academy. He'd not even been raised in the same universe, so if anyone damned him for taking the laws of Time into his own hands, so be it. It was too late to save his mother, even at the height of his grief he'd understood that, but the future he'd seen for Ace could and would be prevented.

Even, he thought grimly, if it turned out to be the last thing he did.

oOo

"So? Where are we going?"

The Doctor turned with a glare as Ace banged open the interior door to the console room. His snappish response died on his lips at the sight of her. Beggar him if she wasn't positively glowing! A suspicion flashed across his mind, to be just as summarily dismissed as none of his business. If his son and Ace were, er, getting on well, that was all for the best. Whatever happiness could be grasped during this grim situation, he was all for it. Besides, even if he did say so himself, she'd done far worse in the past, and never mind how he wasn't supposed to have known about any of her previous beaus. Some things just couldn't be kept secret, at least not without the active cooperation of the TARDIS. So he answered her instead. "Earth."

Ace grinned, unabashed by his curt response. "Unhelpful, that. Time and exact location on Earth?"

"London," he replied, relenting a little. Hadn't he just told himself not to thumb his nose at happiness? "Late 21st century."

"Is this where the Master is?" A little of Ace's unusually good mood evaporated at the idea of a confrontation with Romana's murderer.

The Doctor shook his head, pressed a lever and tapped lightly on a few random-appearing buttons. "No. Susan." The rotor began its usual up-and-down movement, the grinding noise of dematerialization began, and they were off.

Ace's exclamation of surprised delight was interrupted by Kyris' entrance. Unlike Ace, however, his mood was as grim as the Doctor had ever seen. Not that he'd been anything less than serious since their first meeting, but he'd have thought there might be some lightening of mood, to match Ace's. Especially if the reason for her glow was what the Doctor suspected it was...yes, he saw the way Kyris' expression softened as he glanced at Ace, who grinned back at him with a sparkle in her eyes that had nothing to do with the excitement of meeting Susan.

"We're going to see Susan?" Kyris asked, having caught the last bit of their conversation. His expression was concerned. "D'you think that's wise?"

"The Master has no way of tracking us here," his father replied dismissively. "It's perfectly safe." Faced with identical looks of doubt, he insisted: "No, really, it's safe. We're just going to pop in and warn her."

"What, not try to take her with us?" This time the objection came from Ace.

The Doctor shook his head. "I doubt she'd come with us. Her husband and children--"

"Children? So you've got great-grandkids, then?" Ace was delighted by that for some reason.

The Doctor scowled. "Yes," he replied shortly. "We're getting off topic here." He drew a breath, let it out slowly. "She's in no danger from the Master, not directly or though us, but she needs to know what's happening." His expression grew doubtful. "I haven't been to visit since I left her. I do hope my first self made up for that after the business at Rassilon's Tomb." His gaze went inward as he scoured his memories. "Hmm, that seems to be how I recall it. Yes," he added decisively as he turned toward the door to the outside, "that's how I knew about her children. Two boys and a girl." He paused, on the verge of naming them, arrested by a sudden revelation. Their names...so. Susan must know, even if his own memories were, he now suspected, deliberately spotty.

Oblivious to the Doctor's sudden epiphany, Ace had oh-so-casually moved to stand next to Kyris, her hand seeking his behind cover of the console. He squeezed her fingers lightly, brushed the palm of her hand with his thumb, smiling obliquely as she returned the gesture. "So," Ace said as the Doctor fiddled with the door lever to cover his silence, "shall we?" She indicated the door with her free hand.

"Yes, well, perhaps I'd better see her alone," the Doctor muttered, not looking up at the other two as the rotor ground to a halt. The silence was immediately broken by two voices speaking at once.

"Why can't we meet her?" "Perhaps you're right." Ace stared at Kyris, outraged, pulling her hand away from his as he agreed with his father. "No, really," he insisted. "I mean, it could be awkward." He looked over at the Doctor. "It hasn't escaped me that she must be my daughter. If she's actually your grand-daughter and it wasn't just a courtesy title?" He hadn't thought to ask, before.

The Doctor shook his head "no" at the note of inquiry that entered Kyris' voice, while Ace stood, thunderstruck. Obviously she hadn't bothered to put two and two together. "Susan's your daughter?" she asked, in a small, very un-Acelike voice.

Kyris turned to her with a crooked smile. "She'd have to be, wouldn't she? I mean, think about it." Then, as he realized what Ace was thinking: "Not mine yet," he assured her. "Sometime in my future, but also in the past for us all." He faced his father again, noting the irony of his next words even as he spoke them: "Call me a hypocrite, but I'm not ready to face a grown child I haven't even conceived yet."

"I can certainly sympathize," the Doctor murmured in reply. "I shan't take long, I promise." He opened the door and started out, only to stop as Ace darted around the console to join him.

"I still want to meet her," she said belligerently. The Doctor opened his mouth to voice a further objection, then closed it with a resigned shrug as he realized she wasn't going to allow herself to be left out of this one.

"We'll be back soon," she said, not looking at Kyris. He could tell she was angry, but whether it was because he hadn't brought up the likelihood of his being Susan's father earlier or because she wanted him to go with them, he couldn't tell. More likely a mixture of both, he decided as she followed the Doctor out without a backward glance. But it was just as well. He closed the doors after them and stood for a long moment with his hands on the console and his head bowed. When he finally raised his head, he went straight to work on the TARDIS controls.

He still had Ace's future to prevent.