"Look," the man - Chesterton - said. "I'll accept that you may be related to him. But you can't be the Doctor."
The Doctor gave him a stern look, the effect partially ruined by the fact that he was chewing a mouthful of eggs. He swallowed. "Really? Why not?"
Chesterton appealed to his wife for support. "Barbara? Could you help me out here?"
She buttered a scone. "What Ian is trying to say is, we've met the Doctor."
"Of course you have," the Doctor agreed, helping himself to a scone. "Back in 1963. You barged right into my TARDIS. These are really good, by the way."
Ian and Barbara looked at each other. "Yes," Ian agreed, patiently. "We barged into the Doctor's TARDIS. What I'm trying to say here is..." He took a deep breath. "The Doctor is an old man, and shorter than I am. And he doesn't talk like someone from the north."
The Doctor said something incomprehensible, accompanied by a spray of crumbs. Sheepishly, he swallowed and tried again. "He does now. Because I do. And do I really sound like someone from the north?"
Ian massaged the bridge of his nose. "Look. I can accept that you're some relation of his - there's a resemblance -"
"Is there?" the Doctor said in surprise. "I haven't had a chance to check, yet." He looked around. "Do you have a mirror handy?"
"There's a resemblance," Ian continued sternly, "But you look easily 30 years younger."
"Do I? Good. I always hate it when I look older, after I regenerate." He bit off another mouthful of scone, and washed it down with tea. Then he drew a deep breath. "Look. I know you weren't around for it, so this'll be hard to believe. But I regenerate."
"Regenerate?" they both echoed. Barbara sounded interested, while Ian sounded skeptical.
"Yes, regenerate. If I die. Or, more precisely, if my body sustains severe enough injuries to cease functioning. I regenerate. I change form, heal up, and come back to life." He drank more tea. "Well, start functioning again."
He looked at their incredulous expressions. "What? It's something we all do. Did. Could do. All of us."
They both looked skeptical now.
"Yeah, yeah, I know. Sounds like I'm selling you a line, right? So how can I convince you? Obviously, arriving in the TARDIS -" he looked alarmed, now. "I did arrive in the TARDIS, right?"
"Yes," said Barbara. "That's why we're willing to accept that you may be related to the Doctor."
"Right, then," the Doctor said. "I'll need to get back there, later. Check what sort of shape she's in. We had a rough go of it. But if arriving in the TARDIS didn't convince you, what will?"
They shrugged. "Tell us something only the three of us would know," Ian said.
"Right." The Doctor thought a moment. "When we arrived on Skaro, I sabotaged the fluid links to force you to let me explore Kalaan."
"That's in the books."
"Oh." He did a double take. "Books? I'm in books?" A broad smile split his face. "Brilliant! I'm famous!" Then he thought some more. "I had a stuffed panda on the chair in my control room. Susan won it in Brighton, about four months before you barged on to my TARDIS, and gave it to me."
His face clouded at the memory. "She said... she said I was always a gruff old bear, and maybe the panda would help me be a little more friendly."
