You approached it by a door of quite ordinary appearance (no one cares to be seen leaving what is obviously a safe deposit), and you signed your name before entering a lift. You descended forty feet below the surface of the earth, gave a password on emerging from the lift, traversed a corridor, and at length stood in front of the sole entrance to the Safe Deposit. A guardian, when you had signed your name again, unlocked three unpickable, incombustible, and gunpowder-proof locks in a massive steel door, and you were admitted, assuming always that the hour was between nine and six. Out of hours and on Saturday after-noons and on Sundays a time-lock rendered it utterly impossible for any person whatever to turn any key in the Safe Deposit. Once the lock was set, Hugo himself could not have entered, not even to save the British Empire from instant destruction, until the time-lock had run its course. You found yourself in an electrically lighted world of passages built in flashing steel, with floors of steel and ceilings of steel--a world where the temperature was always 65 deg.. Every passage was separated from every other passage by steel grilles, and at intervals uniformed and gigantic officials wandered about with impassive, haughty faces--faces that indicated a sublime confidence in the safety of the multifarious riches committed to their care. You might have guessed yourself in the fell grip of the Inquisition. As a fact, you were in something far more fell. You were in a vast chamber of steel, and that chamber was itself enclosed on all sides by three feet of solid concrete. No thief could tunnel or mine you without first getting through the District Railway on the one hand, or the main drainage system of London on the other. No thief could rifle you by means of duplicate keys, for no vault and no safe could be opened except in the presence of the head guardian, who possessed a key without which the renter's key was useless. No tricks could be played with the gas, because there was no gas, and the electric light could only be turned off or on from the top of the lift-well. Now, it was a singular thing that when Simon Shawn, having proved his identity and his mission at the lift, arrived at the entrance to the Safe Deposit, he discovered the great steel door ajar, and no door-guardian in the leather chair where a door-guardian always sat. This condition of affairs did not affect the essential impregnability of any individual vault or safe, but, nevertheless, it was singular. Simon walked straight in. 'There's no one at the door,' he said to the patrol, whom he met in the main passage. 'I want to see Mr. Hugo at once. He's down here somewhere, or he's been here.' 'Yes, Mr. Shawn,' said the patrol politely; 'I did see Mr. Hugo here about an hour or so ago. I'll ask Mr. Brown. Will you step into the waiting-room?'