If he had been alive before to overlook no possible detail, the concentration with which he now began an inspection of the driveway seemed to include within his scrutiny each separate grain of sand.
"Don't move," he curtly enjoined; McCaleb instantly froze.
Slowly, inch by inch, he went over a space covering the radius of about a rod from where they had paused. Again and again he returned to the footprints in the little depression, and once he passed swiftly back to the point where the first trail diverged from the driveway so abruptly. He examined the solitary heelmark here with an added interest, in the end producing from his pocket a finely graduated ivory rule, which he applied to the print in a variety of ways.
Returning again to the depression, he made a careful comparison by means of the measure. At last he turned to McCaleb.
"I was afraid you would disturb something," he explained. "Our trail is becoming a little involved; it was too plain to last. This promises to be a wonderful case, Mac,—a wonderful case. I wish I were twenty years younger."
"What do you make of it, sir?"
Mr. Converse considered before replying, and when he did his whisper was no more than audible.
"Mac, keep this to yourself, and do not ask me to go any farther into it just now." He threw the light upon the young man's sharp-featured countenance, and subjected it to a momentary but searching scrutiny. "A woman was here," he went on, "and some man; but I'm afraid her identity will cause a devil of a mess."
It was obvious that he was much impressed by what he had read in the driveway, and he presently concluded, in a vastly altered manner:
"You see, Mac, how carefully one must act in a case of this kind; there is never any telling what might turn up, nor what a lot of needless worry—not to say danger—an innocent person may be made to suffer. The fact that a woman figures so prominently in the De Sanchez case, and yet is kept in the shadowy background, coupled with the fact that we have stumbled upon these impressions here, looks pretty bad for that woman if she happens to be the same in both instances. It may be only a coincidence, but a man and woman were here—here when General Westbrook was done to his death, and here when the assassin departed. Why? Now let us drop this as though it had never come to our knowledge—until we know more.... I believe you said Mrs. Westbrook wore some sort of evening gown when you and Clancy got here."