He finished up his ice-cream while he thought about how his reality differed from hers, then sat back, crossed his ankle over his knee, folded his hands behind his head, and looked at her.
"My world's quite different from yours. The Master and I... I haven't seen him since before the Time War. I don't even know if he's still alive. Back in the real world, I assumed he was dead, but when I'm here, I know there's a possibility he's not."
He pursed his lips, and continued. "I met up with you when you were nineteen and you came travelling with me. And we met up with Jack, in London during the Blitz, and he came along with us too. And then he got turned immortal - " he hesitated to say more, unsure what she knew about that - "and I regenerated and - " quickly - "you went home and a few weeks later Jack and I landed up here."