Standing holding a test tube in the flame of a Bunsen burner Sherlock divided his attention between the chemical reactions in front of him, and the equally strong chemical reaction fizzing through him like rockets whenever John was close. As he watched the liquid bubbling in the glass tube he tried to recall if he had ever felt this way before, and if so when and for whom, but nothing came to mind.

Sherlock was nothing if not brutally honest, at least with himself, and as he consulted his notes and added a few more chemicals to the mix he examined any likely ulterior or less than realistic motives. Was it the fact that John had rescued him, had offered him trust and security, befriended him where others had avoided him?

Resting the test tube in a wooden rack he waited, automatically noting the chemical changes, letting the part of his mind that was looking inwards review the last few days.

Although they were opposites in many ways they worked well together, complimented each other, even had the same slightly twisted sense of humour…..

And suddenly it was crystal clear. They were the two halves of one whole.

Like he had craved first drugs, then absolute mental focus and clarity, so Doctor John Watson craved the adrenalin rush of the battlefield.