Sherlock has some training under his metaphorical belt, but John's sudden outburst catches him completely off guard. The first hit he takes in the face, square on, and it staggers him. When John flies at him again, Sherlock throws up his hands, and the first thing that comes to him is wing chun, so he rolls with it, since it doesn't require a whole mess of upper body movement save for the arms and hands. The flurry of blows gets half-heartedly deflected, most getting through to land on him, but then Sherlock has the chance to look into the fury on John's face and something inside of him cracks a little, just a tiny bit.

"John!" roars Sherlock "John, stop!" The lanky frame of the detective goes sprawling as another hit connects, and he just stays on the ground, grimacing visibly (an admission of pain that John might find uncharacteristic as well if he's clear-headed enough to notice.) He stays down though, breathing heavily, his lip and nose bleeding profusely. He turns his head to spit blood out of his mouth, and hopes the doctor doesn't pursue him to the ground.

"Please!" Sherlock gasps, staring up at John with a mixture of pain and - is that fear? mingling in his sharp features.