"What century are we in now," Rose asked looking at the familiar Earth beneath them as they came out of the space-vortex into temporal orbit.

"23rd," The Doctor said. "I thought it would be nice to see Susan."

"Yeah, I could live with that. What's the occasion?"

"It's my birthday," he said nonchalantly. "And for the first time in centuries I have the chance to celebrate it with family."

"Time Lord's have birthdays?" Jack looked surprised.

"Well he was BORN, wasn't he?" Rose answered him scornfully.

"I suppose he was. I HAD heard that Time Lord's are cloned," Jack countered.

"Is there some kind of best-selling book out there '100 myths about Time Lords?'" The Doctor asked. "Where DO you get this stuff from?"

"Spaceport gossip," Jack admitted.

"How can there be that much gossip about Time Lords when The Doctor is the only one left?" Rose asked. "Never mind. I don't think I want to know." She turned to the Doctor and kissed his cheek sweetly. "Happy birthday, anyway. And why didn't you say. I could have bought you a pressy when we were on that planet with all the shopping malls. A new jumper maybe…"

“Leave my jumper out of this,” he growled, though only in fun. He laughed and smiled widely as he set the co-ordinates for his granddaughter’s house in the 23rd century.

"Dare we ask how old you are then?" Jack asked.

"950," he admitted. "And I feel every year in my bones!"

"You look great for it," Rose told him. "But I don't think Susan will have enough candles for your cake."

The arrival of the TARDIS in the garden of the new house in the area of the south suburbs of London Rose knew as Richmond-upon-Thames caused a bit of a stir in the Campbell family. Susan was the first of them to reach it and when the Doctor emerged she flung her arms around him and hugged him tightly.

"It's good to see you, Grandfather," she said. "It really is." And when he told her his reason for coming she was quite overcome. "Oh, I'm so GLAD you wanted to come here."

She brought them into the big garden that actually went down to the banks of the river in a gentle slope. David was trimming the rose bushes and the boys were playing on the lawn. When they saw The Doctor they stopped and ran to him. For a while there was nothing more for the adults to say as he ran and played with them. Rose and Jack sat down with Susan at a table under a big sunshade, with her youngest child on her knee, and watched him.

"He really loves being with the boys," Rose said with a smile.

"Yes," Susan agreed. "I wish he could be here more often. Although… explaining the TARDIS to the neighbours… We should get some kind of carport… to park it." Rose laughed at the idea of a carport for the TARDIS but there was a kind of logic. Susan, the youngest living person to be born on Gallifrey, lived as a Human, in an ordinary Human way except when her extraordinary Grandfather came to visit. Rose reflected that she lived the opposite way. She lived the extraordinary life except when, now and then, they came to Earth. Sitting there with Susan and Jack, in the sunshine, drinking lemonade while The Doctor played tag with the boys, it was all so normal she almost forgot she was in the 23rd century.

After a while The Doctor came to join them. He was smiling brightly and practically bounded into the chair beside Rose. Susan handed him a glass of lemonade and he drank it appreciatively. Susan talked for a while about various trivial things, then she came to one that was most vital to her.

"I really wanted to ask you, Grandfather, about the boys… Their psychic abilities are becoming stronger every day. Better than mine… far better. And I wonder how to teach them about it. I wondered if you could do anything for them."

"No problem." He turned to where the boys were and whistled. They looked around at the sound and came to him. He lifted both of them onto his knee. "Davie, Chris, I want to teach you a game. I am going to show you a picture in your head. Can you tell me what it is?" And he closed his eyes in concentration, and sent a simple image into their minds. Chris, the youngest by minutes of the two, was the first to laugh out loud and tell him the name of the animal he had thought of. Then Davie got one. Then the two of them looked puzzled for a moment.

"That's a…" Chris's face screwed up in concentration. "A…."

"A Slitheen," Davie said triumphantly.

"It's funny looking," Chris laughed.

"Yes, it is," The Doctor agreed. "Although not so much fun up close." And he winked at Rose, who knew full well how thoroughly unpleasant close contact with a Slitheen was. She understood that the boys had not only picked up the image of the Slitheen, but the name of it. They understood more than one kind of information telepathically.

"Now," he said. "Can you show me a picture?" The boys nodded and their faces took on a look of concentration. The next moment the Doctor gave a yell as if in pain. So did Susan. He gently lifted both boys off his knee before standing up. He looked, Rose thought, dizzy, using the table to steady himself. "It was a pterodactyl," he said. "Glad you're learning about Earth history so well. But… let's see if you can send me another picture from right over there. One at a time, this time. Two different pictures." And he pointed to the furthest end of the garden. The time it took for them to run down there was just enough for him to brace himself for the next assault on his mind.

When they came, two jolts that made him gasp and grip the table edge tightly, Rose jumped from her seat and went to him. He clung to her, his head pressed against her shoulder and even without a psychic connection she knew he was in some pain still.

"They need to discipline their power," the Doctor said when his head cleared enough. "If they turned that on an ordinary Human…. they could fry brains."

"That's what I'm afraid of," Susan told him. "At school…"

"Yes." The Doctor nodded. "This is something we can't ignore." He called the boys back to him verbally and settled them on his knee again. "You're a little young," he said. "But I want to tell you some grown up secrets. You two, and your mum, are different from other people. So am I. And because we're different, we have responsibilities. We have to make sure our special powers don't frighten or hurt the other people. So you must NEVER, EVER play that game with anyone but me. You must not tell anyone that you can do that. And you must practice sending your thoughts QUIETLY. Because you gave your old Granddad one heck of a headache and it's no fun having a headache on your birthday." The boys maybe only partly understood what he was telling them, but they gave a promise anyway before he sent them off to play again.

"We DO have a problem," he said to Susan. "They both have at least as strong telepathic capabilities as I do. Chris, I think, is the stronger. But they've no way to channel it or control it. They ought to be beginning training in the disciplines. If we were home…" He stopped and both he and Susan looked sad at the thought of their lost home planet.

"Wait," Jack cut in. "Do I have this right…. Those two kids have the genetics of Time Lords, but the only thing stopping them being the real thing is the right school?"

"It's not as simple as that," Susan said.

"Yes, it is," The Doctor contradicted her. "The problem is that they are growing up Human, on Earth, but they NEED to be growing up as Gallifreyan on Gallifrey. They need the Academy's disciplines. They need the challenge of an advanced education system. I bet they're bored at school, aren't they."

"Yes," Susan admitted. "It all comes too easy for them."

"Just like you, when you wanted to be an Earth teenager in the 1960s," The Doctor said.

"Can't you teach them?" Jack asked the Doctor.

"Some of it," he said. "How to control their abilities, that kind of thing. And they ought to know some of the history of where we come from. They need to know WHY they are different… who we are. But I can't teach them the other disciplines. Even if I had the time…"

"Doctor," Rose said. "I know this is nothing to do with this. But how come I didn't pick up any of the signals? I used to be able to feel when you were using telepathy but now there is nothing."

“I think that was because of SangC’lune,” The Doctor said. “The place had natural safeguards that prevent anyone not of Time Lord blood from using our disciplines. I think the residual power you had was neutralised. And…” He stopped and rubbed his head, which was still hurting from the power of two enthusiastic youngsters with uncontrolled telepathic ability. Through the pain a clear idea came to him.

"SangC'lune."

"What?" Susan looked at him curiously.

"I could take them there. The safeguards wouldn't take their ability away altogetherbecause they ARE Galiffreyan, but because they are untrained it would dampen it a little. So I could teach them how to control the ability without them killing me. And I have some back up there. I might be able to start them off on the way to learning the discipline."

"You want to take my boys away from me?" Susan looked unhappy.

"For a few days," The Doctor assured her. "Just to get them started. And it would be a chance for me to get to know them, too. I really would like to do that."

“I’m not sure what David will say.”

“I hoped you would help me to persuade him.”

“The boys do need help. But David won’t like it.”

She was right. David was not happy at all when the idea was proposed to him.

"Doctor," he said quietly. "It isn't easy for me. I have to accept that my wife and children are not Human…"

"David! You say that as if they are LESS than Human," The Doctor protested.

"I'm sorry," he apologised. "I don't mean that. Though you…. You make me feel inferior when you talk about these things. You're a decent man, and you're Susan's Grandfather - and we both owe you a great deal. But it has always seemed to me that you Time Lord's are the most arrogant and self-righteous people in the universe. And I don't want my children to be that way. I want them to be normal."

"David," The Doctor answered. "You're 100% right. Yes, I am arrogant. Yes. I am self-righteous. But I am also right. And you know I am. Normal for the boys… David, they ARE your sons, but they are of MY blood and it is asserting itself. And normal for them is what I am. I AM a Time Lord."

"Please, David," Susan pleased with him. "If we don't do something… I am afraid for them."

"All right,” he conceded at last. “I suppose it would be all right. After all, if I can’t trust you… You WILL take care of them?”

“David,” The Doctor smiled at him reassuringly. “That goes without saying. I’m their great-granddad.”

David, grey-haired and approaching sixty years of age, looked at The Doctor, who looked at most, 45, despite his true age, and admitted defeat.

"When?" he asked.

"Tomorrow," The Doctor said. "Tonight we're celebrating my birthday."