A mobile phone was ringing on the front table at 221B Baker Street. Mrs. Hudson, who had been busying herself dusting off the book-laden shelves, started slightly when it rang. She called up the stairs to John, who was unpacking, as he had recently returned to Baker Street after a year's time away.
"John! The phone's ringing for you."
"Thanks, Mrs. Hudson," he said, coming down the stairs a bit slower than he would have otherwise, since he had begun to require his walking cane again. As Mrs. Hudson left the room for 221A, he picked up the phone.
"Hello?"
"John! Is that you? Hello! It's the Doctor! How are you?"
"Doctor?" More startled than anything, John simply said, "I'm fine."
"Good to hear! I've got Sam and Dean here with me."
John heard muffled hellos.
"Hello, boys."
"Listen, John, we were wondering if we could stop by for a moment. Something's bothering Dean and he wants to talk to you."
"Well," John said, glancing around at the flat. It looked hardly lived in, for good reason, and there were old newspapers strewn across the table, but it was, he supposed, presentable. "Alright, sure. Pop by, I'll make some tea."
"Thanks, mate," said the Doctor sincerely. "We'll give you a few minutes."
The Doctor let Sam and Dean into the TARDIS, placing the Stetson gently back on its coat rack. On the console, he set her to 221B Baker Street, six minutes in the future, to give John some time to make the tea, and pulled the main lever.