It was half an hour later when a detective entered and spoke to Detective Mallory aside.
"Fine!" said Mallory. "Bring 'em in."
Then there reappeared the woman who had been a prisoner and a man of fifty years.
"Harrison!" exclaimed Bell, suddenly. He staggered to his feet with outstretched hands. "Harrison! I know! I know!"
"Good, good, very good," said The Thinking Machine.
Bell's nervously twitching hands were reaching for Harrison's throat when he was pushed aside by Detective Mallory. He stood pallid for a moment, then sank down on the floor in a heap. He was senseless. The Thinking Machine made a hurried examination.
"Good!" he remarked again. "When he recovers he will remember everything except what has happened since he has been in Boston. Meanwhile, Mr. Harrison, we know all about the little affair of the drug, the battle for new copper workings in Honolulu, and your partner there has been arrested. Your drug didn't do its work well enough. Have you anything to add?"
The prisoner was silent.
"Did you search his rooms?" asked The Thinking Machine of the detective who had made the double arrest.
"Yes, and found this."