Sherlock paused, hesitating. All too aware of the cameras around them, but in the full knowledge that there was basically no where they could go that wouldn't have them. It was achingly difficult not to immediately launch into a detailed and long-winded explanation of everything he had planned, every meticulous detail, but he couldn't. Not without sacrificing everything.

He just hadn't really realised until this moment what it was going to cost him. That look on John's face read worlds, and Sherlock wanted nothing more than to assure him, to point out the cameras and smirk, but it was impossible.

So instead he would have to keep acting, even to his best friend. Even alone.

Because the truth was, here, they were never alone.

"... Not good," He said slowly, as if realising it.