“You have orders to admit no one, constable?” I asked.

“That’s so, sir,” he replied.  “We’re waiting for Detective-Inspector Gatton, who has been put in charge of the case.”

“Ah!  Gatton,” I muttered, and, stepping aside from the expectant group, I filled and lighted my pipe, convinced that anything to be learned I should learn from Inspector Gatton, for he and I were old friends, having been mutually concerned in several interesting cases.

A few minutes later the Inspector arrived—­a thick-set, clean-shaven, very bronzed man, his dark hair streaked with gray, and with all the appearance of a retired naval officer, in his well-cut blue serge suit and soft felt hat; a very reserved man whose innocent-looking blue eyes gave him that frank and open expression which is more often associated with a seaman than with a detective.  He nodded to several acquaintances in the group, and then, observing me where I stood, came over and shook hands.

“Open the door, constable,” he ordered quietly.

The constable produced a key and unlocked the door of the small stone building.  Immediately there was a forward movement of the whole waiting group, but: 

“If you please, gentlemen,” said Gatton, raising his hand.  “I must make my examination first; and Mr. Addison,” he added, seeing the resentment written upon the faces of my disappointed confreres, “has special information which I am going to ask him to place at my disposal.”

The constable stood aside and I followed Inspector Gatton into the stone shed.

“Lock the door again, constable,” he ordered; “no one is to be admitted.”

Thereupon I looked about me, and the scene which I beheld was so strange and gruesome that its every detail remains imprinted upon my memory.

The building then was lighted by four barred windows set so high in the walls that no one could look in from the outside.  Blazing sunlight poured in at the two southerly windows and drew a sharp black pattern of the bars across the paved floor.  Kneeling beside a stretcher, fully in this path of light, so that he presented a curious striped appearance, was a man who presently proved to be the divisional surgeon, and two paces beyond stood a police inspector who was engaged at the moment of our entrance in making entries in his note-book.

On the stretcher, so covered up that only his face was visible, lay one whom at first I failed to recognize, for the horribly contorted features presented a kind of mottled green appearance utterly indescribable.

Stifling an exclamation of horror, I stared and stared at that ghastly face, then: 

“My God!” I muttered.  “Yes! it is Sir Marcus!”

The surgeon stood up and the inspector advanced to meet Gatton, but my horrified gaze had strayed from the stretcher to a badly damaged and splintered packing-case, which was the only other object in the otherwise empty shed.  At this I stared as much aghast as I had stared at the dead man.