After an hour’s work Russell admitted his failure. "It doesn’t seem to make any sense," he said.

"You must not get discouraged so easily," Crossle said.

"Many of the messages we had to deal with in the American Black Chamber took months of painstaking analysis. The chief asset of a successful cryptographer is a bulldog tenacity against seemingly insurmountable obstacles."

He took Russell’s cross-section paper and underlined certain letters as follows:

"'S.S. York - midnight - ten thousand troops,'" Russell read slowly. "That’s rather a tough one."

"You’ll learn to spot the message readily with practice," Crossle reassured him. "The message was received by a U-boat off the Long Island coast, probably through a telescope."

"Who was the airplane pilot?" Russell asked.

"An army instructor at Roosevelt Field, a chap with an excellent record in every respect. Which goes to prove that when it comes to espionage no one is above suspicion."