"Well," said the Doctor, "because of the lack of conventional documentation of Earth Slayers, even as a Time Lord I was rather obliged to track her personal history forward from the the date when I had then last met her, by the same means as a more timebound historian would use."
"So you just traced her through public records," said Xander, "from - when was it - January 1998 until you discovered her death recorded as of May 2001."
"Yes. I discovered the records of Giles' headstone purchase, and his order for what was carved on it."
"And you looked no further?" Tara asked.
"Why, no." What a curious thing for her to say.
"I have someone for you to meet," said Anya.
--
The Doctor found himself on the couch without knowing how he'd gotten there. "What happened?"
"You fainted," said Buffy.
"I never faint," said the Doctor.