Sherlock gave the address to the taxi driver and settled himself into the back seat. As he watched the grey London streets pass by, he truly felt like he was coming home. For a brief moment, he wished it was Baker Street he was heading to, but he was only too well aware of why it wasn't.
He reached into his pocket and pulled out the phone and the key that Mycroft had given to him. He had obtained a key for both John's building and his flat after Greg had called round. Greg had relayed his very clear concern about John and had almost ordered Mycroft - Sherlock wished he had been present for that conversation - to get keys made in case anybody needed to get in. As Sherlock fiddled with them in his hand, he felt anxious. He really wasn't sure what kind of reception he would get from the man who had thought him dead for so long. The man who had inadvertently caused his life to completely derail.
For a moment, Sherlock felt self-doubt. Perhaps this wasn't a good idea. Maybe Mycroft should have told John about Sherlock first. He glanced outside, realising it was too late for second thoughts now. He had to get back to John; to show him there was still something worth living for; to bring him back to life.
The phone in his hand began to vibrate, disturbing his train of thought.
"Yes?" he said quietly, his hesitation and tone both giving away his nerves.
"Sherlock." Mycroft's voice was controlled, of course it was, but it also held something else; something important, "How far away from John are you?"
Sherlock peered out at the streets, identifying landmarks and noting street names and calling on his rusty south London knowledge in order to reply.
"Five minutes." he responded, double-checking his bearings as the taxi made a right turn, "I think."
Mycroft was silent for a minute before speaking again.
"I hope that isn't too long, Sherlock." he eventually said, and the soft sound of silence indicated that he had rung off.
Sherlock knew exactly what Mycroft meant.
He hoped so too.