After Sherlock died three years ago, John moved out, but he came back every Sunday for brunch with Mrs. Hudson. Soon Molly joined him and, after a while, Lestrade.
This Sunday Mrs. Hudson had forgotten the milk, so John offered to pop over to the store and pick some up. As he left the apartment, giggling at something Lestrade said, there was a knock on the front door. "I'll get it," he called out.
And then he opened the door and saw the ghost of Sherlock standing on the front stoop.
John's first thought was that he had finally snapped, but a loud gasp behind him told him that Mrs. Hudson had poked her head out of her home and seen the apparition as well. He couldn't turn around to see her, though. He couldn't move. He could only stare, dumfounded. His leg, still traitorously tied to his psyche, decided that it no longer knew how to function and began to give way. Before he could hit the floor, though, wiry arms reached out to catch him, pulling him into the warmth of a wool coat which smelled of chemicals. It was Sherlock. Alive.
Words crowded John's throat. How? Why? You bastard. I missed you. But all he could say, as his arms wrapped around a thin waist, was "Welcome back."