"He accidentally dropped some cards from his pocket-book when giving Merrington an address at his flat last night, and one of them was Wendover's business card. Merrington did not see it--it would have conveyed nothing to him if he had--but I did. Nepcote knew that I saw it, and must have realized that I suspected him. He has been watching my rooms and followed us here, or he has been hanging around this place to see if I called on Wendover." "Even now I do not see the connection. If Wendover told us the truth, Nepcote has not been to him with the necklace. Then what did it matter to Nepcote whether you came here or not?" "Nepcote may have been the man who offered the diamond to Wendover." "That is impossible. Wendover says that man called some days before the murder." "Still, it may have been Nepcote." "That goes beyond me," said Caldew, with a puzzled look. "What are you implying?" "Nothing at present. Every step in this case convinces me that we are faced with a very deep mystery. It isn't worth while to hazard a guess, because guessing is always unsatisfactory." "Perhaps we had better try and get a little more out of Wendover," said Caldew. "That would be merely waste of time. He has not got the necklace, and he is unable to describe the man who offered him the diamond. I believe now that it was Nepcote, but that doesn't matter, one way or another. It is far more important to know that he came here to-day to watch for us. That implies that he had reason to fear investigations about the necklace. The inference to be drawn is that Nepcote is responsible for the disappearance of the necklace, and is, therefore, deeply implicated in the murder." "Perhaps it was not Nepcote that you saw?" suggested Caldew. He felt that the remark was a feeble one, but he was bewildered by the sudden turn of events, and in a frame of mind which clutches at straws. "Put that doubt out of your mind," said Colwyn. "I saw his face distinctly. He had disappeared by the time I got down. The alley where he was standing commanded a view of the entrance of this building. I ascertained that by standing in the same spot. His flight is another proof--though that was not needed--of his guilty knowledge and complicity in this murder. Why should he run away? According to his own story last night he had nothing to fear. But now, by his own actions, he has brought the utmost suspicion on himself." "I suppose it is no use searching about here for him?" remarked Caldew, glancing gloomily out of the doorway. "Not in the least. The neighbourhood is a warren of alleys and side streets from here to Grays Inn Road." "Then I shall go up to his flat at once," said Caldew. "He has not had time to go back."