Jerce smiled. "Eve's curiosity," he answered; "however, I am not a woman, so I refrained from unsealing the envelope, and after a time I slipped it, with some other papers, into my safe, and thought no more about the matter. But when this grey man attacked me the other night, the incident was recalled to my mind, but not," added Jerce, with emphasis, "not until Ferdinand told me that he had seen a man in grey clothes with a scar on his cheek. I then returned to London and opened the envelope. I found therein a paper containing a name and address." "What were they?" asked Anthony, who was listening attentively. "Alfred Osip, 14, Rough Lane, Stepney. Also there were a few lines, stating that the man who wrote them--my consumptive patient--and Osip were the surviving members of the Purple Fern gang, and that if Osip's room in Stepney were searched, papers proving the guilt of all would be found. Well, then, Mr. Ackworth, one man has been hanged, another has died of consumption, and the third, Alfred Osip, is the person who attacked me on that terrace, and no doubt, in the struggle, dropped this golden box, which at one time undoubtedly contained the india-rubber stamp used to mark the victims." "I see," said Clarice, "but why should Osip attack you, doctor?" Jerce looked at her in surprise. "My dear, you are usually quicker in seeing things," he said, rebukefully. "Of course, Osip in some way knew that his dying accomplice had betrayed him, and that I carried the sealed letter--as he thought--on my person. That was why he searched. I should have had him arrested, when Ferdinand suggested going for the police; but I never dreamed that the wretch was connected with the Purple Fern gang. However, I have made what amends I can. I went at once to Scotland Yard, and told the authorities what I have told you. Now, this warning to Horran--undoubtedly sent by Osip--and this box, will be valuable evidence. He may be caught red-handed, if he attempts the murder. But you can see now, Mr. Ackworth, why I suggest that you should not inform the local police. Osip is cunning and dangerous, so it will be advisable for us to get a detective from London to see into the matter. I fear the Crumel police may bungle the business. I return to London this afternoon--or, to be precise, this evening, so I shall at once communicate this new discovery to the Scotland Yard authorities." Ackworth nodded. "I think your plan is the best, Doctor," he said, in a meditative voice, "only I hope this brute will not murder Mr. Horran in the meantime." "I suggest that Chalks should remain constantly with Mr. Horran." "Will not that arouse Mr. Horran's suspicions?" asked Anthony. "After all, in his delicate state of health, it will not do to let him know that he is in danger of death."