For long enough after Gatton's departure I sat thinking over our conversation. Despite the lateness of the hour at which he had departed, he had had no thought of rest and was setting out in quest of further evidence to point to the author of Sir Marcus's death. The room was laden with tobacco smoke, for our conference had lasted more than two hours, but dusk was very fully established and when presently as I sat there in the dark contemplating the horrible labyrinth into which my steps had drifted, Coates entered.  
"Ah, Coates," I said, "light up."
 
He switched on the electric light and I saw layers of smoke—clouds drifting from the open window towards the newly opened door.
 
"Shall you be going out again to-night, sir?" asked Coates, standing rigidly to attention as was his custom when addressing me.
 
"I think not, Coates," I replied. "I have done enough for one day, but I should be glad if you would ring up the New Avenue Theater and inquire if Miss Merlin will speak to me. It will be about time now for the performance to have finished."
 
"Very good, sir," said Coates, and proceeded to make the call, whilst I sat listlessly smoking and listening to his voice. Presently:
 
"Miss Merlin did not appear to-night, sir," he announced: "she is indisposed."
 
"I thought as much," I muttered. "I could hardly have expected after such a day of horror and excitement that she would have been capable of appearing to-night. Ring up her flat, Coates," I added. "I should like to speak to her, for I know she is in great trouble."
 
"Indeed, sir," Coates permitted himself to remark. "Is it something to do with the discovery at the docks this morning, sir?"
 
"It is, Coates," I replied. "It is an utterly damnable business."
 
"Indeed, sir," said Coates again, and went to the telephone.
 
Three minutes later I was talking to Isobel.
 
"I find it utterly impossible to tell you what has happened," she declared, "since I saw you last. I feel incapable of thinking, and of course it was quite out of the question for me to go to the theater to-night. But it is not so bad as it might have been." She hesitated, then: "I was only able to give them very short notice unfortunately, but from a selfish point of view, as you know—I was leaving the stage—very shortly—"
 
"Yes," I answered dully, "I know; but have you seen the police?"
 
"I have seen Inspector Gatton," she replied; "but as he told me that he was coming along to you, no doubt you know what took place."
 
"No," I replied; "he did not mention the visit, but you quite recognize the fact, Isobel, that he does not regard you as being in any way concerned in this ghastly affair."
 
"He was awfully kind," she admitted; "in fact I quite changed my opinion regarding the methods of the police authorities after my interview with Inspector Gatton; but although he was so extremely tactful with me, I really cannot forgive him his suspicions, which he was at scarcely any pains to disguise, regarding Eric."
 
"Regarding Eric!" I exclaimed.
 
"Oh," continued Isobel, "he may have concealed his views from you, as he knows that you are—a friend of Eric's; but he was less careful about concealing them from me. To all intents and purposes Eric is under police surveillance!"
 
"But this is utterly incredible!" said I. "You don't mean to tell me, Isobel, that Coverly has persisted in his silence respecting his movements last night? If he has done so, in the circumstances he has only himself to thank. Social position and everything else counts for nothing when an inquiry concerning a murder is concerned. He knows that perfectly well."
 
I think I spoke hotly, and certainly I spoke with a certain indignation, for I very strongly resented Coverly's attitude in the case, which could only add to the difficulties and sorrows of Isobel's position.
 
Yet a moment afterwards I regretted that I had done so, for:
 
"Are you going to quarrel with me, too?" she asked pathetically.
 
"What do you mean? Who has been quarreling with you?"
 
"Eric quarreled with me fiercely at the solicitors' to-day, and when I begged of him to be frank respecting his movements last night, his attitude became"—she hesitated—"almost unbearable. He did not seem to realize that I was only thinking of him, nor did he seem to realize the construction which I might have placed upon his silence. I mean, Jack, what can he possibly have to conceal?"
 
Temporarily I felt myself to have become tongue-tied. What could it be that Coverly was concealing? The idea of complicity in the crime I scouted; nothing could have induced me to believe it. Only one explanation presented itself to my mind, as evidently it had presented itself to Isobel's—another woman. However:
 
"You may depend," I said, endeavoring to speak soothingly, "that he has some good and sufficient reason for this silence, and one which is not in any way discreditable. Nevertheless he will have to reconsider his attitude in the near future. Of course there are times when almost every one of us would be hard put to it to establish an alibi if we were called upon to do so—as regards witnesses of our movements, I mean; but at least we can state roughly where we were during any hour of the day, even if we have to trust to luck to find witnesses to prove the truth of words. His attitude of silence, Isobel, is ridiculous."
 
"Have you seen the evening papers?" she asked pathetically.
 
"Some of them," I replied.
 
"They have got my name in already," she continued, "and my photograph appears in one. It is outrageous how they leap at an opportunity for scandal."
 
"It will all be cleared up," I said, speaking with as much confidence as I had at my command. "You know and I know that Coverly is innocent and I don't believe that Gatton thinks him guilty."
 
A while longer we talked and then I returned rather wearily to my chair in the room where the air was still laden with tobacco fumes.
 
Without believing it to contain any very special significance as I had supposed, but merely attracted by the strangeness of the passage, I remembered how Gatton had harped upon Maspero's description of the attributes of Bâst. "Sometimes she plays with her victim as with a mouse," etc. The big book with its fine plates, several of them representing cats similar to that which Gatton had left behind for my more particular examination, still lay open upon the table, and I reread those passages appertaining to the character of the cat-goddess, which I had marked for Gatton's information. Scarce noting what I read—for all the time I was turning over in my mind the manifold problems of the case—I sat there for an hour perhaps, in fact until I was interrupted by the entrance of Coates.
 
"Shall you require me again to-night, sir?" he inquired.
 
"No," I replied; "you had better turn in now, as in all probability we shall be early afoot to-morrow, Coates. Inspector Gatton will probably be calling for me."
 
"Very good. Good-night, sir," said Coates; and performing a smart about-turn, he walked out of the room.
 
I went on reading, not in quest of any particular information, but in that idle mood when one reads anything, interesting or otherwise. For a time I heard my conscientious batman fastening doors and............