These are the persons of our drama, with whom we already are familiar; but there were still two other persons in that room, whose acquaintance we have yet to make. One was Sir Derwent Dewsnap, whose surgical fame, one hardly need remark, was world-wide. Few men have performed more operations than Derwent Dewsnap; few have done more cutting and carving on the outside and inside of the human frame--and, as a cynic once observed, he looked it. But, while his knowledge and experience of general surgery was great, his skill in dealing with the human cranium, and especially that part we call the brain, it has been stated, was almost superhuman. Nowadays every great surgeon is a specialist, and Dewsnap's speciality was brain. Not, of course, in a mental sense; he was not a mental pathologist at all; but in operations on the brain he was _facile princeps_. He was shortly going to perform one of the most delicate operations on the cranium which even he had ever undertaken; and these persons were gathered together to receive from him an expression of opinion as to his probabilities of success. The other person to whom we have yet to be introduced was Plashett--Alexander Plashett; a name which has only to be mentioned in order to conjure up a vision of one of the greatest criminologists who ever made a practical study of the law. What Plashett did not know about crime and criminals was not worth knowing. He had caused so many scoundrels to reap the just reward of their ill-doings, and so many more to get off scot free, that it was actually whispered, where those things are whispered, that on whichever side Plashett was the gentlemen of the jury were. Of course that was not a whisper which was to be taken precisely at the foot of the letter; but it undoubtedly was a fact that counsel would rather be briefed by Plashett than against him. He was there in that room to represent the interests of certain persons who might find themselves in a very uncomfortable position indeed if there was an unfortunate termination to the operation on which Sir Derwent was so shortly to be engaged. Thus, while no one cared a button for the person on whom the operation was about to be performed, everybody hoped that he would come well out of it--which seeming paradox is explained by the fact that the person in question was Mr George Emmett; and that if he died in Sir Derwent Dewsnap's hands one of the individuals in that room would quite possibly be hanged for him. Therefore, when the Earl of Strathmoira put a question to the great surgeon his reply was anxiously awaited. "So it seems, Sir Derwent, that, to perpetrate what sounds like a bull, the odds are even?" Sir Derwent was a precisian even in words, as he immediately made plain.