"You mean Radnor's behavior on the day of the murder and his refusal to explain it?" I asked uneasily.
"No," Terry laughed. "That may be significant and it may not—I strongly suspect that it is not. What I mean, is the peculiar place in which the crime was committed. No person on earth could have foreseen that Colonel Gaylord would go alone into that cave. There is an accidental element about the murder. It must have been committed on the spur of the moment by someone who had not premeditated it—at least at that time. This is the point we must keep in mind."
He sat for a few moments staring at the dashboard with a puzzled frown.
"Broadly speaking," he said slowly, "I have found that you can place the motive of every wilful murder under one of three heads—avarice, fear or revenge. Suppose we consider the first. Could avarice have been the motive for Colonel Gaylord's murder? The body had not been robbed, you tell me?"
"No, we found a gold watch and considerable money in the pockets."
"Then, you see, if the motive were avarice, it could not have been immediate gain. That throws out the possibility that the murderer was some unknown thief who merely took advantage of a chance opportunity. If we are to conceive of avarice as the motive, the crime must have been committed by some person who would benefit more remotely by the Colonel's death. Did anyone owe him money that you know of?"
"There is no record of anything of the sort and he was a careful business man. I do not think he would have loaned money without making some memorandum of it. He held several mortgages but they, of course, revert to his heirs."
"I understood that Radnor was the only heir."
"He is, practically. There are a few minor bequests to the servants and to some old friends."
"Did the servants know that anything was to go to them?"