“I’m not an æsthetician,” Markham reminded him, a trifle testily. “I’m merely a practical lawyer, and when it comes to determining the authorship of a crime, I prefer tangible evidence to metaphysical hypotheses.”
“Your pref’rence, my dear fellow,” Vance returned blandly, “will inev’tably involve you in all manner of embarrassing errors.”
He slowly lit another cigarette, and blew a wreath of smoke toward the ceiling.
“Consider, for example, your conclusions in the present murder case,” he went on, in his emotionless drawl. “You are laboring under the grave misconception that you know the person who prob’bly killed the unspeakable Benson. You admitted as much to the Major; and you told him you had nearly enough evidence to ask for an indictment. No doubt, you do possess a number of what the learned Solons of to-day regard as convincing clues. But the truth is, don’t y’ know, you haven’t your eye on the guilty person at all. You’re about to bedevil some poor girl who had nothing whatever to do with the crime.”
Markham swung about sharply.
“So!” he retorted. “I’m about to bedevil an innocent person, eh? Since my assistants and I are the only ones who happen to know what evidence we hold against her, perhaps you will explain by what occult process you acquired your knowledge of this person’s innocence.”
“It’s quite simple, y’ know,” Vance replied, with a quizzical twitch of the lips. “You haven’t your eye on the murderer for the reason that the person who committed this particular crime was sufficiently shrewd and perspicacious to see to it that no evidence which you or the police were likely to find, would even remotely indicate his guilt.”
He had spoken with the easy assurance of one who enunciates an obvious fact—a fact which permits of no argument.
Markham gave a disdainful laugh.
“No law-breaker,” he asserted oracularly, “is shrewd enough to see all contingencies. Even the most trivial event has so many intimately related and serrated points of contact with other events which precede and follow, that it is a known fact that every criminal—however long and carefully he may plan—leaves some loose end to his preparations, which in the end betrays him.”