The Doctor hears voices down the hall: Captain Jack and Rose, who have finally located him. "Good evening. Hope I'm not interrupting? Captain Jack Harkness." He sticks out his hand and says he's been hearing all about the good Doctor. "He knows," Rose says, very secret-agenty. "I had to tell him...about us being Time Agents?" The Doctor nods, all but putting a finger against his nose. "...And it's a real pleasure to meet you, Mr. Spock," says Captain Jack, patting the Doctor heartily and familiarly on the shoulder, and then walking off, leaving the Doctor looking rather bemused: "'Mr. Spock'?" They take a break for a joke that's surely already been made in the last forty years, but is still somewhat funny: "What was I supposed to say? You don't have a name! Don't you ever get tired of 'Doctor'? Doctor Who?" I think it's the balls-out nature of the joke that makes it funny. I haven't nailed it down yet for sure, though. He says that, after nine hundred years, "Doctor" is good, and then he takes her to task for going on a stroll in the middle of the London Blitz. Rose: "Who's strolling? I went by barrage balloon -- only way to see an air raid. Listen, what's a Chula warship?" The Doctor stands stock still, because it's been like forty minutes and he forgot she was awesome.