The young man and the girl looked at each other and smiled. Their experience had not tended to make them credulous. Had he lived, Hermann Banf would have been, for Wharton, the star witness against a ring of corrupt police officials. In consequence his murder was more than the taking off of a shady and disreputable citizen. It was a blow struck at the high office of the district attorney, at the grand jury, and the law. But, so far, whoever struck the blow had escaped punishment, and though for a month, ceaselessly, by night and day "the office" and the police had sought him, he was still at large, still "unknown." There had been hundreds of clews. They had been furnished by the detectives of the city and county and of the private agencies, by amateurs, by newspapers, by members of the underworld with a score to pay off or to gain favor. But no clew had led anywhere. When, in hoarse whispers, the last one had been confided to him by his detectives, Wharton had protested indignantly.
"Stop bringing me clews!" he exclaimed. "I want the man. I can't electrocute a clew!"
So when, after all other efforts, over the telephone a strange voice offered to deliver the murderer, Rumson was sceptical. He motioned the girl to switch to the desk telephone.
"Assistant District Attorney Rumson speaking," he said. "What can I do for you?"
Before the answer came, as though the speaker were choosing his words, there was a pause. It lasted so long that Rumson exclaimed sharply:
"Hello," he called. "Do you want to speak to me, or do you want to speak to me?"
"I've gotta letter for the district attorney," said the voice. "I'm to give it to nobody but him. It's about Banf. He must get it quick, or it'll be too late."
"Who are you?" demanded Rumson. "Where are you speaking from?"
The man at the other end of the wire ignored the questions.
"Where'll Wharton be for the next twenty minutes?"