legalistic logic can successfully withstand the most obst'nate and heroic assaults of ordin'ry common-sense."
Markham was piqued.
"Still harping on the St. Clair woman's innocence, eh? However, in view of the complete absence of any tangible evidence pointing elsewhere, you must admit I have no choice of courses."
"I admit nothing of the kind," Vance told him; "for, I assure you, there is an abundance of evidence pointing elsewhere. You simply failed to see it."
"You think so!" Vance's nonchalant cocksureness had at last overthrown Markham's equanimity. "Very well, old man; I hereby enter an emphatic denial to all your fine theories; and I challenge you to produce a single piece of this evidence which you say exists."
He threw his words out with asperity, and gave a curt, aggressive gesture with his extended fingers, to indicate that, as far as he was concerned, the subject was closed.
Vance, too, I think, was pricked a little.
"Y' know, Markham old dear, I'm no avenger of blood, or vindicator of the honor of society. The rôle would bore me."
Markham smiled loftily, but made no reply.
Vance smoked meditatively for a while. Then, to my amazement, he turned calmly and deliberately to Markham, and said in a quiet, matter-of-fact voice:
"I'm going to accept your challenge. It's a bit alien to my tastes; but the problem, y' know, rather appeals to me: it presents the same diff'culties as the
