Disclaimer - I don't own Doctor Who, the BBC does. Thank god for fan fiction, yes.
" You're a grandfather ?"
The Doctor looked at the girl in astonishment, " Susan ?" he whispered in disbelief.
Susan smirked, " I see your brain hasn't improved in speed much, has it ?"
The Doctor wasn't willing to take that, he'd already faced wreckage from TARDISes, found out Time lord had been killed and their body parts were used to patch people up, so he wasn't going to accept this, not unless she showed more proof.
" But, the Time lords are gone. I left you in the 22nd century, you shouldn't even be here." The Doctor said.
Susan looked disappointed, " I travelled, I went to other realities." she patted the side of her TARDIS affectionately, " I didn't spend 34 years with your clone in Pete's world for nothing, how would I know that if I'm an impostor ?"
The Doctor floundered on, he wasn't willing to put his hopes up again. That almost cost him his life, his TARDIS and Amy and Rory.
" But - "
Susan interrupted him, " Shut up, I've had a long journey. What's wrong with you ? This regeneration seems more paranoid than the last."
The Doctor cocked his head, " You've met my clone ?" an earlier comment had popped into his mind.
Susan simply said, " Yes." then she saw that it would take more than that to convince her reticent relative. " Alright, 1963, we stopped off. On business," she added, not wanting to let the humans know of the Hand of Omega; Susan felt that would lead to very irritating questions. " I went to Coal Hill school, where I attracted the attention of two teachers; Ian and Barbara, their married by the way, we travelled back to prehistoric times, you then dragged them to Skaro, we encountered the Thals and the Daleks-"
" Daleks ?" Amy interrupted. Both Time lords glared at her, Susan carried on, " You removed the fluid link because you wanted to explore their city, endangering our lives because you were curious. I bet you regret that now, especially since our race is gone." Susan spat at him.
The Doctor staggered back, " It really is you, isn't it ?" he whispered quietly, sounding like a child.
Susan folded her arms, " You can hear my thoughts in your head, I'm right in front of you, my TARDIS, which I created myself and it wasn't easy, by the way, is right in front of you. Why are you being like this ? I know about your tussle with the Master, but I'd have thought you'd be pleased to see me."
The Doctor shifted his feet, " I am, it's just…." he sighed. " I've just come from a pocket universe, I found this," he picked up the psychic distress box that the message came from and handed it over to Susan.
She examined it, seeing the circle symbol, " The Corsair, he survived the war ?"
The Doctor's face became grim, " That's what I thought at first, but I found that he was dead, his TARDIS was dead, its energy was consumed by an entity the size of a planet. House, the entity, tried the same trick with my TARDIS."
The Doctor gave Susan a brief summary of the recent battle, the TARDIS losing power, Idris, the psychic distress boxes, the TARDIS junkyard, the battle Amy and Rory had had with House and Nephew. By the time he finished, Susan's hand was running over her TARDIS as if to sooth her feelings. She could feel her TARDIS' anxiety.
The Doctor saw this and tried to reassure her, " Don't worry, House is gone. He allowed the TARDIS consciousness back in and she killed him."
Susan felt mildly reassured, but she was still troubled, " If there's one TARDIS junkyard, why not another ?"
Amy interrupted before the Time lords could continue, " Sorry, but Doctor," she turned to face the Doctor, " but who is this woman ?"
The Doctor jumped, remembering his manners," Oh sorry, Amy, Rory, this is Susan, she's my granddaughter. Susan this is Amy and Rory, my present travelling companions,"
Susan looked at both Amy and Rory, both humans seemed surprised. Rory was the first to speak, " But, after all that with House, I thought there were no other Time lords. How can she still be alive ?"
Susan answered him, " I didn't fight in the war, I was travelling in other realities. The number of differences between our reality and others is beyond count, you wouldn't believe it."
The Doctor asked a question he'd been holding back, " You have a TARDIS, one that you said you created ?"
Susan smiled, looked around the TARDIS, and turned her attention back to her listeners, " When I was a child, my parents let me operate TARDISes, but I didn't like them. Any of them. So I created one with features others lacked. For a start, my TARDIS can travel through other realties without worrying about the walls of the universe. Until I arrived in Pete's world I had no idea our people were gone."
Amy couldn't keep silent, " How could you know that ? If you were in another reality…"
" I met the Doctor's clone," Susan said. " During the last years of his last incarnation, the tenth Doctor almost, almost, regenerated. He siphoned the energy off, it was triggered and a clone was made. The Doctor had a psychotic companion called Rose Tyler who he left in the parallel universe with the clone. All because he killed Daleks."
Susan looked at her grandfather, " I hope I don't meet your tenth life. He sounds a little sanctimonious to me. They were only Daleks, they killed our race. What were you thinking ?"
The Doctor didn't reply.