“At noon, yesterday, a young man came into the office and demanded to see me. He said he was a taxi driver — which proved to be true, so far as I can learn — and that he was going to sue a client of mine. His story sounded so convincing that the girl in the outside office was alarmed.”

JOE CARDONA smiled. He remembered the indifferent way in which he had been received by that very girl. He pictured the same taxi driver as a glib sort.

“When the fellow came in here, Joe,” continued Blefken, “he refused to give his name. He admitted that his story was a bluff. His real purpose was to deliver a letter to me, in person — and he made it plain that I must let no one know about it!”

“What was the letter?”

“I’m getting to that. The taxi driver said that it had been given to him by a man in the dark. The fellow had approached him, and had seemed very nervous.

“The stranger had told the driver to get the letter to me before the next evening — and in payment, he had given the man a hundred-dollar bill. The taxi driver produced it. He wanted it changed.”

Cardona laughed. He scented a hoax.

“No, Joe!” said Blefken, with a faint smile. “It wasn’t a counterfeit bill. I sent it out to be changed — told the girl to take it to a certain teller at my bank.

“I didn’t say a word about where I had gotten the bill. But I know that particular teller well. If it went by him, it would be genuine. It went by. The change came back.

“Meanwhile the taxi man was convincing me that he was playing the game fair. He said that the man who gave him the letter had climbed into his cab to plead with him.