We hurried off together accordingly. Hewitt knew nothing of the case he had to examine, and so could tell me nothing, beyond the short urgent request that he would come at once, and that the matter involved the loss of bonds to a very large amount; and he dropped me at a convenient spot, whence my walk to the hospital was but a short one. I saw my friend McCarthy, and bothered him very successfully for nearly an hour, getting all the information I had expected, and more, during a very interesting walk through the great hospital. "You get some idea in a place like this," said McCarthy, as we came at last into the receiving room for accident cases, "you get some idea, Brett, of the size of this great London machine working about us. You might walk about the streets for a week and never see a serious accident, or even an accident at all, and yet, you see, here they come all day long--a stream of people damaged or killed in the machine." A decent workman was having a gashed hand dressed and strapped, and a navvy with bandages about his head was being led away by a friend. Nurses and dressers were waiting ready to take their orderly turns at the incoming casualties, and as we looked a more serious case was brought in on an ambulance by two policemen. The patient was a ragged, disreputable-looking fellow of middle age, in grimy and tattered clothes, whose head had been roughly bandaged by the policemen who brought him. He had been knocked down and kicked on the head by a butcher's cart-horse, it seemed, in Moorgate Street, and he was quite insensible. A very short examination showed that the case was nothing trivial, and McCarthy sent me to sit in his private room to wait lunch, while he gave the matter his personal attention. When he returned he brought a small crumpled envelope in his hand. "That case is put to bed," he said, "still insensible." "Is it very bad?" I asked. "Slight fracture of the occipital, and, of course, concussion of the brain--probably contusion, too, I expect we shall find presently. Not so over serious for a healthy man, but I'm afraid he's an old soaker--the sort that crumple up at a touch. Nobody knows him, and there's nothing to identify him in the pockets--a few coppers, an old knife, and so on. So we can't send to tell his friends--unless we bring in your friend Martin Hewitt to trace 'em out, which would come too expensive. Besides," McCarthy added, dropping into a seat before his desk, "if he's got any friends they'll come, sooner or later, when they miss him. This is the only thing he'd got beside what's in the pockets--he'd been sent on a message, probably."