Mr. Meredith started to say something and swallowed it with an effort.
"I know it positively, yes," he replied. "I received this letter dated the second from him three days ago, and to-day I received a cable-dispatch forwarded to me here from Baltimore."
"Are you positive the letter is in your son's handwriting?"
Mr. Meredith almost choked in mingled bewilderment and resentment at the question and the manner of its asking.
"I am positive, yes," he replied at last, preserving his tone of dignity with a perceptible effort. He noted the inscrutable face of his caller and saw the corrugations in the brow suddenly swept away. "What business of yours is it, anyway?" blazed Mr. Meredith suddenly.
"May I ask where you were last Thursday night?" went on the even, steady voice.
"It's no business of yours," Mr. Meredith blurted. "I was in Baltimore."
"Can you prove it in a court of law?"
"Prove it? Of course I can prove it!" Mr. Meredith was fairly bellowing at his impassive interrogator. "But it's nobody's business."
"If you can prove it, Mr. Meredith," remarked The Thinking Machine quietly, coldly, "you had best make your arrangements to do so, because, believe me, it may be necessary to save you from a charge of having stolen the Randolph gold plate on last Thursday night at the masked ball. Good-day, sir."