"Good-evening, Mr. Mallory," responded the scientist in the thin, irritated voice which always set Mr. Mallory's nerves a-jangle. "I don't suppose you would tell me by what steps you were led to arrest Mr. Herbert?"
"I would not," declared Mr. Mallory promptly.
"No, nor would you inform me of the nature of the evidence against him in addition to the jewels and plate found in his possession?"
"I would not," replied Mr. Mallory again.
"No, I thought perhaps you would not," remarked The Thinking Machine. "I understand, by the way, that one of your men took a leather cushion from the automobile in which the thieves escaped on the night of the ball?"
"Well, what of it?" demanded the detective.
"I merely wanted to inquire if it would be permissible for me to see that cushion?"
Detective Mallory glared at him suspiciously, then slowly his heavy face relaxed, and he laughed as he arose and produced the cushion.
"If you're trying to make any mystery of this cushion, you're in bad," he informed the scientist. "We know the owner of the automobile in which Herbert and the Girl escaped. The cushion means nothing."
The Thinking Machine examined the heavy leather carefully and paid a great deal of attention to the crusted stains which it bore. He picked at one of the brown spots with his penknife and it flaked off in his hand.