They were lying in bed one night. Not quite yet drifting off, still holding each other, when Rose asked, "Doctor?"
"How many times have you been in love in your life?"
The Doctor's eyes popped open. After a moment of thought, he said, "This is a trap."
Rose laughed. "It's not, honestly. I really want to know."
The Doctor looked into Rose's eyes. "Rose, you're the love of my life. You know that, right? If I had to choose between all the people I've loved and you…"
"Doctor, no. You don't have to say that," Rose said quickly. "It's just… You've lived a very long life. You must have loved and lost a lot of people, and I want to know all about you. I want to know the people you've known."
The Doctor stared at her a moment. "You're not jealous?"
"No." Rose smiled. "You love me now and I know you wouldn't leave me for anyone. I believe in us, but I want to know what came before us. It's a part of who you are."
The Doctor smiled. "Alright. I've loved a great many people in my life, but Romantic love… It's not as many as you'd think."
"Just four before you," he said.
"In nine hundred years?"
The Doctor pondered for a second whether this was a good time to tell her he'd been rounding down his age by a century or two since he met her. No. That was a conversation for another time. "Yup," he answered.
"Who were they?" she asked. "What were they like?"
"Well, my first love started when I was just a boy," he said, eyes drifting off to thoughts of the past. "We met when we were very young. No idea what love really was yet. We grew up together at school. We were together for ninety years."
"That's a long time," Rose marveled.
"Well, for a Time Lord, ninety is the equivalent of a human's eighteen."
"Oh. What happened?"
"He changed," said the Doctor sadly.
Rose was surprised to hear that this long relationship had been with a man, but only slightly. After Jack, the idea of fluid sexuality came easily to her. After all, if the Doctor had regenerated into a woman, she knows she would still love him. Or her rather. Only this Doctor couldn't regenerate anymore, so she'll never know what that would have been like. "What was his name?" she asked.
"When we were at school, he was called Koschei. He, like me, chose a different name when we graduated."
"What was your name at school?" asked Rose.
"I will tell you, only if you promise never to call me by it."
Rose smiled. "I promise. Unless I'm really cross with you."
The Doctor sighed. "Theta Sigma," he said.
"But that's not your true name."
"No," he said.
"Why can't you say it?"
"Well in Time Lord tradition, you could only say it on one of two occasions. Upon your final death or on the day of your wedding, because our names have great power. Most Time Lords chose their death, because most Gallifreyan marriages were arranged. But my name was different. I once used my name to seal a great rift in the universe, so if I spoke it, all of time and space would fall. There would be nothing but silence. But in this universe, things are different. I can say it here," he smiled.
"Will you tell me?" asked Rose.
"I'm saving it for the wedding," he said. "But I can hardly wait."
Rose smiled. "Okay, who else?"
"You were telling me about your great loves."
"Well, after the Master, there was Jamie."
"Oh, that's what he changed his name to after graduation."
"But that's one of the universes I walked through on my way to find you," she said astonished. "He'd taken over the Earth!"
"I said he changed," said the Doctor solemnly.
"I'll say." She resolved to bring this up later, but let it lie for now.
"Anyway, after him, there was Jamie McCrimmon." He smiled fondly. "Such a bright young man. He was a Scottish Highlander. I picked him up from the Battle of Culloden. Then there was Romana. Oh, she always matched me wit for wit. She was actually more intelligent than me. Eventually she left me to do greater things. She actually became president of Gallifrey."
"Really?" said Rose, amazed. "Must've helped to have friends in high places."
"Well, I was president too, for a time."
"Yes. Sort of an absentee president, but it still counts." He continued, "After that there was Charley. Charley Pollard. She was wonderful! Smart and brave and kind and stubborn. So much like you, really." Then he got very sad. "But she, um… she left me." He cleared his throat and moved on. "But then there was you. Wonderful, beautiful you."
"What about you?" he asked. "Who did you love before me?"
"Well, my first love was probably not actually love. More of an infatuation. I hate him now."
"Yeah. Cheating bastard." she spat.
"Then Mickey?" asked the Doctor.
"No, actually," she said. "There was someone else. About a week after I kicked Jimmy stone to the curb, I was at a party at Shireen's. I was looking for a rebound, but I found so much more. I was eighteen. He was twenty. We caught each other's eyes at the party. He was dancing like a loon and made me laugh. Then we danced together. He was dressed oddly for his age. Bowtie and tweed jacket and braces. Not how someone would usually dress for a party. His name was John." she stopped for a moment. "He never told me his last name, actually."
As Rose talked, the Doctor started to get this strange feeling.
"Anyway, we talked all night, then I asked him out for coffee the next day. By the end of that date I felt like I'd known him forever. We were together for just two weeks, but it felt like a lifetime was squeezed into that short period. One morning I woke up in his flat and he was gone. He'd left me a note, though."
By now the Doctor had the distinct feeling that this had been a future version of the self that had left them on the beach at Bad Wolf Bay just a month ago. "What did the note say?" the Doctor asked.
"That the last two weeks had meant everything to him, that he had to leave, but he couldn't tell me why, that he'd love me for the rest of his life, and he told me to have a fantastic life. I remember those words specifically, 'Have a fantastic life', because you echoed them in Emergency Programme One."
The Doctor was sure of his suspicions now.
"There was one other thing," said Rose.
"What?" the Doctor asked, lump in his throat.
"I said he never told me his last name, and I never told him mine either, but he signed it 'I love you, Rose Tyler'" She looked up at the Doctor and saw his eyes glistening, saw the way he was looking at her, and she knew. "Oh my god. It was you!"
"I think so," he said. "Some future incarnation of myself must have gone to you for one last chance to be with you."
"But doesn't that break the laws of time?"
"Not really. That's why he never told you who he really was. That's why he left, because he, I, knew I'd meet you next year. The only reason I can think that I would do that, though was if I thought I was going to die soon."
"Oh, my god!" she cried. "Do you think he's dead?"
"I don't know. It might have been centuries after we last saw him, so it might have been his last incarnation."
"I hope he lived for a very long time and found happiness and love again."
"I hope he did too, Rose" he held her tight. "I hope so too."