The idea is this,” began Sir Hubert, as Vassily delicately circulated his mixture: “you all know the usual version of the Murder Game. One person is chosen as the murderer, his identity being concealed from all the players. They scatter, and he seizes his moment to ring a bell or bang a gong. This symbolizes the ‘murder.’ They collect and hold a trial, one person being appointed as prosecuting attorney. By intensive examination he tries to discover the ‘murderer.’ ”

“Excuse me, please,” said Doctor Tokareff. “I am still, how you say, unintelligible. I have not been so happy to gambol in sush a funny sport heretobefore, so please make him for me more clearer.”

“Isn’t he sweet?” asked Mrs. Wilde, a good deal too loudly.

“I will explain my version,” said Sir Hubert, “and I think it will then be quite clear. To-night at dinner one of us will be handed a little scarlet plaque by Vassily. I myself do not know upon which of the party his choice will fall, but let us pretend, for the sake of argument, that Mr. Bathgate is cast by Vassily for the part of the murderer. He will take his scarlet plaque and say nothing to anybody. He has between five-thirty to-morrow afternoon and eleven tomorrow night as the time allotted for the performance of his ‘murder.’ He must try and get one of us alone, unknown to the others, and at the crucial moment tap him on the shoulder and say ‘You are the corpse.’ He will then switch off the lights at the main behind the stair wall.