“On the day preceding the murder, I had made up my mind to have one more try with Hume; and if that failed I intended to follow Spatola’s advice, break in and take the plans by force.  I was so full of this resolution that I could not contain myself; I hinted at it to Miss Vale; and the result of that hint, you know.”

He leaned his face forward in his hands and seemed to give way to a bitter train of thought.  He was evidently despondent.

“It was also some such hint upon your part that induced her to visit Locke at Dr. Mercer’s place, wasn’t it?”

Morris raised his head and nodded.

“Yes,” he said.  “After the murder I suspected Locke at once of having something to do with it.  I told Miss Vale; she went there without my knowledge—­seeing that I had not the courage to go myself,” he added bitterly—­“and demanded the plans.”

“And she learned that they were still at Hume’s—­behind the portrait?”

“Yes.  Locke told her—­he was overcome with horror at the murder.  He had merely desired to secure the plans,—­having somehow learned their hiding place.  He had no intention of killing Hume.”

“But why did Sagon do it?—­he must have had it in mind when he bought the bayonet at Bernstine’s,” said Pendleton, looking at Ashton-Kirk.

“He had.  Do you recall how Burgess’ report spoke of a league of smugglers in Europe of which Hume was a leading spirit, and also of how they had been captured and nearly all but Hume were tried and convicted?”

“Yes.”

“Sagon was one of those convicted.  The diamonds which Hume tried to smuggle into this country were to have been turned into money at the time of the gang’s arrest and the proceeds spent in their defense.  But instead of doing this, Hume left his comrades to their fate and absconded.  When Sagon gained his freedom he began a search for Hume, meaning to have revenge.  This search finally led him to Locke as a person who had known Hume, and who would be likely to be able to tell where he could be found.”

“Sagon has told you this?” queried Pendleton.

“Yes; he talked freely, after he saw that his case was hopeless; and he, too, insisted that Locke did not intend to commit murder.  Locke, even at the time of his meeting Sagon, was looking for someone to aid him in gaining possession of the Morris plans.  The work-shop which we saw beside Locke’s house contained a monoplane in course of construction; but there was something lacking which he felt Morris’s plans could supply; and so he was anxious to get hold of it by hook or crook.

“Sagon, whose purpose from the first was murder, was not at all averse to combining it with something else.  He took the room at Mrs. Marx’s place, after he had perceived that an entrance could probably be made at Hume’s by way of the scuttle.  The well dressed ‘business guys’ that the machinist on the first floor spoke about to us, were no doubt Locke, who frequently called upon Sagon, and Mr. Morris here, whom the man did not suspect of being a lodger.