A few minutes later the house was filled with detectives, police photographers and coroner’s officers. They came on a useless errand, for the door remained locked. Tab took advantage of their arrival to escort his friend home. Before he went, Carver drew him aside. “We shall have to keep in touch with Mr. Lander,” he said. “He may be able to throw a great deal of light upon this murder. In the meantime I have sent out all station calls to pull in Felling--who is Wellington Brown?” “Wellington Brown? That is the man who has been threatening Trasmere--I told you about him at lunch.” Carver pulled an old pair of gloves from his pocket. “Mr. Wellington Brown was in that underground corridor,” he said quietly, “and was sufficiently indiscreet to leave his gloves behind--his name is written inside!” “You will charge him with the murder?” asked Tab, and Carver nodded. “I think so. Either he or Walters. At any rate, we shall hold them on suspicion, but I cannot be more definite until we’ve got inside that vault.” Tab escorted his friend to the flat, and leaving him, hurried back to Mayfield, by which fanciful name Trasmere had called his grim house. “We’ve found no weapon of any kind,” said the detective whom he found sitting in Trasmere’s dining-room with a plan of the house before him. “Maybe it is in the vault, in which event it looks like a case of suicide. I have been on the telephone with the boss of Mortimers, the builders. They say that there is only one key in existence for that vault--I was speaking to Mr. Mortimer himself and he knows. Trasmere made a special point about the lock and had twenty or thirty manufactured by different locksmiths. Nobody knows which one he used, and Mortimer says that the orders were so imperative that there should be no duplicate key, that it is unlikely--in fact, I think, impossible--that the murderer could have entered the vault except by the aid of Trasmere’s own key. However, we shall soon know; I have the best workman in town working at the unfinished key in Felling’s room and he says it is so far advanced that he is in no doubt he will be able to open the vault tonight.” “Then it is useless in its present state?” The other nodded. “Quite useless, we have tried it and the locksmith, who is an expert, says that it wouldn’t fit into the keyhole as it was when we found it.” “Then you suggest it is a case of suicide? That old man Trasmere went into the vault, locked himself in and then shot himself.” Carver shook his head. “If the revolver is found in the vault, yours would be a very sound theory, though why Trasmere should shoot himself is entirely beyond me.” At a quarter to eleven that night three men stood before the door of the Trasmere vault, and the shirt-sleeved workman inserting the key, the lock snapped back. He was pushing the door open when Carver caught his arm.