She slipped out into the darkness and was gone. Geoffrey stooped and bent over a dark blot or two that lay on the stone still at the bottom of the window. "Blood," he muttered, "blood beyond a doubt. It was no delusion of mine." From outside came the swish of silken drapery. It was Mrs. May returning. She seemed herself again by this time. "The danger is past," she said, "if danger you choose to call it. The next time we meet we shall laugh together over this comedy. I assure you it is a comedy. And now I am going to ask you to leave me." The woman was playing a part and playing it extremely well. With less innate knowledge, Geoffrey would have been thoroughly deceived. As it was, he affected to make light of the matter. He held out his hand with a smile. "I am glad of that," he said. "You must let me come again, when, perhaps, you may be disposed to allow me to assist you. Good-night and thank you for one of the pleasantest evenings of my life." The door closed behind Geoffrey, and he stumbled along in the darkness until his eyes became accustomed to the gloom. Out in the road some one crept up to him and laid a hand on his arm. Like a flash Geoffrey had him by the throat. "Speak, or I will kill you," he whispered. "Who are you?" "Come with me at once," came the hoarse reply. "And release that grip of my throat. I am Sergius Tchigorsky." CHAPTER XXI THE MYSTERY DEEPENS Geoffrey recognized the deep rasping tones of Tchigorsky directly. His hand dropped to his side. No need to tell him that danger was in the air. It was the thick, still kind of night that goes with adventure. "Something has happened?" Geoffrey asked. "Something is going to happen unless we prevent it," Tchigorsky replied. "The enemy has been foiled three times lately and is getting uneasy. He begins to realize that he has to cope with somebody who understands the game. It is no use to work in this deadly mysterious fashion as long as certain people can read the danger signals and act upon them, and therefore it has been decided to fall back upon more vulgar methods. You are not afraid of danger?" "Not in the least. Try me." "The danger is great. You are dealing with some of the cleverest people on earth. If you are discovered you will be put away. Your courage will be tested to the utmost. Are you ready?" Geoffrey hesitated but for a moment. His senses seemed to be braced and strengthened. He seemed to hear better all at once; his eyes penetrated farther into the gloom. There was a feeling of eagerness, of exultation upon him. He took Tchigorsky's lean claw and laid it upon his left wrist. "Feel that," he said. "Is not my pulse steady? I am longing to go forward. Only give me a chance to find the truth." Tchigorsky chuckled. This was the kind of grit he admired.