"Nice to meet you," said Joyce. Then, because the Doctor's last traveling companion had been a half-Vulcan Time Lady, the natural next question seemed to be, "Where are you from?"
"A long time ago, in a galaxy far, far away ..." said Padme.
"You missed the trauma in the trauma center," Buffy was telling the Doctor, in the living room where the gang was gathered. Despite his continual protestations that he wasn't a medical doctor, the Time Lord was insisting on examining Buffy's crowbar puncture, though the wound was already mostly gone. "Glory cornered Dawn at the hospital." When the Doctor looked at the Slayer sharply, Buffy added, "Glory doesn't know. But Dawn knows. So does the gang."
"Ah," said the Doctor. He immediately abandoned Buffy, probably reckoning - not far from accurately - that Dawn was in more need of whatever professional help his title qualified him to give. "Thereby the trauma, I suppose."
"At least I know what I really am now," said Dawn. "Anyway, as far as anyone around here knows what I really am." The attempt at her normal level of affected sullenness was only mostly successful.
The Doctor knelt in front of Dawn's seat on the living room couch. "Who you really are, Dawn. What is truth? As a time-sensitive I know that reality is much more plastic than humans believe, even than those humans do who deal with the supernatural.
"But remember: All our memories of who you are from more than six months ago may, or may not, be false - but all of them since then are true." He looked her in the eyes and smiled as he said this, and it helped.
"You told the Doctor?" Willow had pouty-face bearing on Buffy again for the second time in twenty-four hours and on the same subject. "You didn't tell us, but you told the Doctor?"
"Uh, I - I - I had to tell the Doctor," Buffy stammered.
"With my sensitivity, I might've been able to help," said the Doctor carelessly.
"Actually," Giles said to the gang, "we told the Doctor because we were afraid his sensitivity would reveal the situation to him only partially, and that he'd then charge off and give it all away."
"Hang on!"
"In the event, of course, he was as subject to the working's effects as any of us, so we needn't have worried."
"Hang on!!"