His brain worked with lightning rapidity. Could it be that the key to the cipher was contained in those words? This seemed to be a logical conclusion. No one had gotten in touch with him previously to suggest a key. Until a key was found no cipher except those of the simplest forms could be solved.
The full force of Agent “X’s” extraordinary deductive powers focused on the problem. All types of ciphers were known to him. The key words of most did not contain repeated letters. The word “secret” for this reason would not be likely to constitute a key. “X” was too short. This left “agent” as the most logical possibility.
“X” drew up charts of the best-known ciphers. He tried the word “agent” in various positions without results, finally arriving at the diagraphic cipher known as the Playfair. This had often been used in the World War.
He made the necessary twenty-five letter box, put the word “agent” at the top — its natural position — and went to work on the message again. Then almost instantly his eyes brightened. The first four letters of the first group, “BTXA,” spelled “have.”
Quickly, with the expert ease of a man trained in cipher and code work, he deciphered the other groups, using the vertical, horizontal, and diagonal letters on the Playfair diagram he had made. The result was a message more significant than even he had anticipated.
“Have information concerning menace threatening peace and safety of country. Please communicate through paper in same cipher to arrange meeting. Speed imperative.”
For many seconds “X” studied this message. The dynamic light of intelligence in his eyes seemed to glow like a living torch. Was this a trap, set by the DOACs themselves, after learning somehow that he was active against them? Or was it from some one willing to take a desperate chance and become an informer against the DOAC organization? For the wording of the message made “X” certain that it referred to the DOACs in one form or other.
Working carefully with his diagram, using the Playfair cipher again, with the word “agent” as the key, he enciphered an answering message.
“Confidential. YKKEI DALAS EPLGF DUZRA PLXAP DIXBE EFOIQ EGTUN AMTNH UAMTC NHIEU FMKTO-NUHMP SAOLN PMUKR EMDIM MIYQEV.”
Translated, this message read:
“Will be in parked coupé River Boulevard and Morgan Street, nine tonight. Flash lights four times. I will follow. Secret Agent ‘X.’”
He figured the word rate on this, according to the paper’s published schedule, then put the message and the money in a sealed envelope addressed to the paper’s personal column. Out in the street he went quickly to a telegraph office twelve blocks away. Here, without giving his name or address, he handed the envelope to a special messenger for immediate delivery to the newspaper. It would appear in the next afternoon’s edition where the eyes of the Agent’s mysterious correspondent would surely see it.
Chapter II
TWENTY-FOUR hours later, a smart coupé turned into River Boulevard, heading uptown. The lights of other cars showed beetle-like along the wide thoroughfare. On the black river the ports of ferries and steamers twinkled.
The man at the car’s wheel bore no likeness to E.E. Winstead. His features were such that one would have said there was not even a family resemblance. Yet he was the same man who had read and answered a message in the Playfair cipher through the columns of the paper.
So plastic and flexible was the strange, volatile material used by “X” in his disguises that it seemed living flesh. The new features he had created, though unlike Winstead’s, were just as commonplace. For the Agent didn’t want to attract attention to himself. And, just as he had taken precautions to make an elaborate disguise, so he had taken other precautions.
Concealed in hidden pockets of his suit were nearly a half dozen of the odd devices he was in the habit of carrying.
The coupé he was in, seemingly an ordinary stock model car, had sheets of light-weight armor plate along the back and sides. This plate, of the finest manganese steel, was proof even against machine-gun bullets. The Agent had used it tonight, half suspecting he was walking into a trap.
Even in this armored car he knew he was challenging death. But fear had no place in his dangerous, desperate work. Fear he had cast out long ago. His pulses were beating with excitement now, with the thrill of the chase, with the hope that the mysterious code message and the man he was to meet in the next half hour would throw some light on the strange activity of the dreaded DOACs.
In the fast-moving cars he passed were couples and groups of well-dressed people on their way to evening entertainment. Soon they would be drinking, dancing, laughing, sitting in comfortable seats at popular shows.
Their gay and smiling faces were in sharp contrast to the dark, brooding menace Agent “X” had set himself to combat. Yet, if that menace were allowed to go unchecked, the secure world that these people knew would end. There would be bloodshed, misery, terror spread across the face of America. The DOAC organization with its poisonous, insidious propaganda would rise like a savage tide sweeping all before it.
The corner lights of Morgan Street appeared directly ahead. The Secret Agent pressed the brake pedal of his armored coupé. No other car was parked here now. His own would appear plainly to the unknown cryptographer when he passed.
Agent “X” backed his coupé into Morgan Street, facing the boulevard, ready to go in either direction if a strange car should signal him to follow. His own parking lights were on. He turned off the dashboard light. In the dark interior of the car he sat, waiting, smoking cigarettes, eyes watchful.
Once a black limousine came along Morgan Street and passed him. There were four men in it. The Agent tensed, prepared to hear the crash of bullets. But the car rolled by, the men did not look his way. A policeman swinging his nightstick sauntered down the block, passed out of sight. The traffic along the boulevard appeared to thin. The Agent looked at his watch.
Ten minutes to nine. The city crowds, pleasure bent, had already arrived at their destinations. The hour of “X’s” strange rendezvous was drawing near.
He watched every car that passed now with an intent gaze that missed nothing.
Nine came. A minute went by — two — and then the Agent sat straight forward in his seat, hand poised over the gear shift of his coupé. For a small sedan was rumbling by. There was a lone man at the wheel. As he came opposite Morgan Street, the man turned his head for a bare instant. Then the tail light and front headlights of his car winked four times.
Smoothly Agent “X” meshed his clutch, and released the brake. Smoothly he rolled onto the wide boulevard. But his eyes were focused intently on the car ahead. Its red tail light was a secret symbol of mystery.
The sedan had not slackened its pace. Only by that brief, winking of light had the man in it betrayed that he was responding to the Agent’s ciphergram.
“X” turned into the boulevard and rolled after the car ahead. He cut down the intervening space till the sedan was only the distance of a half city block in front of him. He was following as he had said he would, waiting now for the man to lead the way.
Ten blocks farther, and the driver of the sedan turned off the boulevard. He sought a side street, a wide thoroughfare in the uptown residential section of the city. Here he kept up the same steady pace and the Agent followed.