“Yes, those are all their things—­coats, hats, stick, and umbrella.”

“And those coats were searched, you say?”

“Yes.”

“And this is the drawer—­thoroughly searched, of course?”

“Oh, certainly; every drawer was taken out and turned over.”

“Well, of course I must assume you made no mistake in your hunt.  Now tell me, did anybody know where these plans were, beyond yourself and your two men?”

“As far as I can tell, not a soul.”

“You don’t keep an office boy?”

“No.  There would be nothing for him to do except to post a letter now and again, which Ritter does quite well for.”

“As you are quite sure that the drawings were there at ten o’clock, perhaps the thing scarcely matters.  But I may as well know if your men have keys of the office?”

“Neither.  I have patent locks to each door and I keep all the keys myself.  If Worsfold or Ritter arrive before me in the morning they have to wait to be let in; and I am always present myself when the rooms are cleaned.  I have not neglected precautions, you see.”

“No.  I suppose the object of the theft—­assuming it is a theft—­is pretty plain:  the thief would offer the drawings for sale to some foreign government?”

“Of course.  They would probably command a great sum.  I have been looking, as I need hardly tell you, to that invention to secure me a very large fortune, and I shall be ruined, indeed, if the design is taken abroad.  I am under the strictest engagements to secrecy with the Admiralty, and not only should I lose all my labor, but I should lose all the confidence reposed in me at headquarters; should, in fact, be subject to penalties for breach of contract, and my career stopped forever.  I can not tell you what a serious business this is for me.  If you can not help me, the consequences will be terrible.  Bad for the service of the country, too, of course.”

“Of course.  Now tell me this:  It would, I take it, be necessary for the thief to exhibit these drawings to anybody anxious to buy the secret—­I mean, he couldn’t describe the invention by word of mouth.”

“Oh, no, that would be impossible.  The drawings are of the most complicated description, and full of figures upon which the whole thing depends.  Indeed, one would have to be a skilled expert to properly appreciate the design at all.  Various principles of hydrostatics, chemistry, electricity, and pneumatics are most delicately manipulated and adjusted, and the smallest error or omission in any part would upset the whole.  No, the drawings are necessary to the thing, and they are gone.”

At this moment the door of the outer office was heard to open and somebody entered.  The door between the two offices was ajar, and Hewitt could see right through to the glass door left open over the barrier and into the space beyond.  A well-dressed, dark, bushy-bearded man stood there carrying a hand-bag, which he placed on the ledge before him.  Hewitt raised his hand to enjoin silence.  The man spoke in a rather high-pitched voice and with a slight accent.  “Is Mr. Dixon now within?” he asked.