"That doesn't explain why he said he was a fake, though. Because he wasn't, and he wouldn't lie about that willingly, I mean," said Sam. John had finished his story and the other three were now discussing the possibilities.
"There's always a chance he was threatened. Moriarty might have forced him to do it," said the Doctor.
Smash! A shattering of glass. Something small and fast rocketed behind the Doctor's head, so close that he felt his hair ruffle, and embedded itself in the wall above the sofa.
"GET DOWN!" Dean bellowed. John and Sam dropped to a crouch, but the Doctor was already at the wall beside the window, peeking around, trying to see who had fired the shot. If they'd wanted any of us dead, we'd be dead already. That had likely been a warning shot. Mrs. Hudson could be heard crying out at the noise, downstairs.
John had grabbed his gun from a kitchen drawer and Sam and Dean had removed their own, which they had been concealing in their jackets. The Doctor rolled his eyes, but didn't protest. There were more pressing problems.
"We need to get there," he said, pointing out the window to the second floor of the building across the street. The sniper he'd seen at the window of the building had gone. "We need to move. Now!" said Dean, but the Doctor was sprinting down the stairs and out the door. The others followed slower at first (uttering swift hellos to Mrs. Hudson, who had appeared in the hall) but faster when they saw the man the Doctor was chasing down the street.
Dean raised his gun, but the Doctor, still running, swung his arm behind him to point the sonic at it. It didn't fire. He then aimed the screwdriver at the red telephone box that the stranger was sprinting past, which immediately exploded, sending the man flying sideways into an electrical pole, where his head slammed against it, and he collapsed to the ground.
The Doctor caught up to the stranger, whose head was bleeding from hitting the pole, but not heavily enough to be deadly. His body was held up awkwardly by the barrel of the rifle strapped to his back.
John caught up to him first. He'd forgotten his walking cane in the living room. He knelt down to examine the sniper, tilting his head up to take his pulse, and the Doctor saw his face clearly. The same man had been spray-painting the building.
"Do you recognize him, Doctor?" said Dean. "Doctor?"
But while Sam was lifting the sniper to be brought back to 221B, the Doctor was all the way back down the block, eyeing the graffiti with trepidation.
Dean picked up the rifle, and he and John followed Sam back to the Doctor.
"What is it?" John asked the Doctor.
He was still looking at the graffiti, which read, in a kind of pixel-like style, four letters: Y-A-N-A.
He tried to stay completely calm, but his mind had sprung into action, generating a myriad of worst-case scenarios. That sniper hadn't been sending a warning. It was a message. The Face of Bo's last words lingered in his ears - you are not alone.
But how could those words have followed him here? Their subject was long gone, he was certain. He had to be. If he'd escaped-
His thoughts snapped back to the present.
"Doctor," John had placed a steady hand on his shoulder, "what's wrong?"
Focus. "Nothing. We should get back inside. Bring the sniper upstairs with you. I'll take the TARDIS indoors."