"It is not so easy as you imagine," he said. "The Secret House contains more secrets than we can at present unravel. It was built, evidently and obviously, by a man of extraordinary mechanical genius as Farrington was, and the primary object with which it was built was to enable him on some future occasion to make his escape. I am perfectly certain that any attempt to raid the house would result immediately in the bird flying. We have got to wait patiently." "What I cannot understand," said his chief, after awhile, "is why he should make a dramatic exit from the world." "That is the easiest of all to explain," smiled T. B. "He was scared; he knew that I identified him with the missing Fallock; he knew, too, that I strongly suspected him of the murder of the two men in Brakely Square. Don't you see the whole thing fits together? He imported from various places on the Continent, and at various periods, workmen of every kind to complete the house at Great Bradley. Although he began his work thirty years ago, the actual finishing touches have not been made until within the last few years. Those finishing touches were the most essential. I have discovered that the two men who were shot in Brakely Square, were separately and individually employed in making certain alterations to the house and installing certain machinery. "One was a young architect, the other was a general utility man. They were unknown to each other; each did his separate piece of work and was sent back to his native land. By some mischance they succeeded in discovering who their employer was, and they both arrived, unfortunately for them, simultaneously at the door of Fallock or Farrington's house with the object of blackmailing him. Farrington overheard the conversation; he admitted as much. "He stood at the door, saw them flourishing their pistols and thought it was an excellent opportunity to rid himself of a very serious danger. He shot them from the doorway, closed the doorway behind him, and returned the revolver to its drawer in his study, and came down in time to meet the policeman with energetic protestations of his terror. I smelt the powder when I went into the house; there is no mistaking the smell of cordite fired in so confined a place as the hallway of a house. And Lady Dex was also there; she must have witnessed the shooting." "Why did she come?" asked the chief. "My conjecture is that she came either to confront Farrington with evidence of his complicity, which is unlikely, or else to secure confirmation of the story her lover told in his last letter." "But why shouldn't Farrington disappear in an ordinary way--or why need he disappear at all?" asked Sir George. "He had plenty of credit in the city. He had the handling of his niece's fortune. He could have blocked out your suspicion; he is not the kind of man to be scared of a little thing like that."