When Two Becomes Three

After returning to London after being shot, the last thing John thought was going to happen was become flatmates with a self proclaimed sociopath. But how can he be a sociopath if he's got a son? And what are the two hiding? All John knows is that he's along for the ride, and that's more than ok with him. Parent!lock, maybe eventual Johnlock, side Mystrade, fluff, R&R