A LIGHT clicked; the rays of a green-shaded light focused upon the polished surface of a table top. The gleam revealed a rectangular sheet of paper, covered with strange, queerly formed characters. It was the photostatic copy of the code found in the secret drawer of Henry Marchand’s desk.

Beside the code lay a pile of papers. All else was in blackness.

Two slender, white hands appeared beneath the light. Quick-moving, sensitive fingers distributed papers from the pile until the table top was covered with the slips.

These papers bore penciled notations. Evidently they had been made in an effort to solve the code. They represented hours of work which had been halted and was now being resumed.

The hands produced a sheet of thin cardboard, its surface filled with carefully cut holes. The fingers moved the cardboard and placed it upon the photostatic copy of the code. Only certain characters showed through the holes in the cardboard.

The hands worked swiftly, changing the position of the cardboard in an effort to form new combinations of visible characters.

The code was now being submitted to a thorough test. The hands went from one sheet of paper to another, seeking some bit of information that might lead to the desired result.

At times the hands paused and remained motionless. When they did, the most unusual feature about them was a gem that glowed from a ring on the third finger of the left hand.

The stone was a girasol, that strange jewel sometimes called the fire opal. Its depths reflected a deep crimson light that glowed like a living coal.

The hands rested upon the table, so motionless that they resembled carved ivory. The brain that controlled those hands was thinking, puzzling over some problem that confronted it.

One hand disappeared and produced a watch. The timepiece, glittering on the table, registered five minutes after ten.

Time passed. The watch recorded midnight.

Then came a hollow laugh from the darkness above the hands. Soft and sinister, the laugh echoed from the invisible walls of the room until it became nothing more than a ghostly whisper.

The hands shot into action. They swept up the slips of paper and deposited them upon the copy of the code. The right hand carried away the watch. A click; the light went out.

Again came the laugh. It pervaded the solid darkness. Then the room was silent. The being who had occupied it was gone.

A TAXICAB rolled up Broadway shortly after midnight. Several persons hailed it at intervals, thinking that it was empty. The driver paid no attention to them, for he had a passenger.

The man in the back seat was shrouded in darkness. He was clad in black that rendered him almost invisible from the street. His face was hidden beneath the broad brim of a black hat. His head was bent forward. His unseen hands were at work. Their long fingers were stroking the sides of the man’s face, as in an effort to change the features which existed there.

The cab stopped at a brownstone house on Eighty-first Street. The passenger reached through the partition and paid the driver. He opened the door and stepped from the cab.

The driver looked about him in amazement. He realized that the door of the cab had opened; but what had become of the rider? In some mysterious manner the man had disappeared when he reached the sidewalk.

The driver shrugged and drove on.

THE house where the cab had stopped was the residence of Henry Marchand, deceased. Its thick, sullen portals and shuttered windows indicated that the building was empty. But there was a light upstairs in the room which had once been Marchand’s sanctuary.

There, at the desk which the old man had used, sat Doctor George Lukens. The physician was lost in thought. Before him lay the unfolded sheet of paper that bore the original code found in Marchand’s desk.

The physician’s brow wrinkled as he vainly studied the code. The oddly formed characters resembled the letters of an unknown alphabetical system. Doctor Lukens was at loss to find a starting point. He rubbed his forehead.

Forgetting the code for the moment, he drew a letter from his pocket and read it mechanically. He placed his finger upon one paragraph in the letter.

“We have been entirely unable to solve this code,” he read half aloud. “It does not correspond to any system of code message that we have ever before encountered. We have no clew as to the system employed. It is something entirely new.”

The physician tossed the letter to the side of the desk. Once again he began his study of the original code.

He mumbled as he stroked his chin.

“The experts cannot solve it,” were his words. “Since they have failed, what can I do?”

It was not a sound that made Doctor Lukens raise his head. He was governed, instead, by one of those strange impulses that all human beings have felt — the mental impression that some other person is close at hand and watching.

This influence became so strong in the mind of Doctor Lukens that he suddenly forgot the code, leaned back in his chair, and glanced to the right. Then he started in amazement.

Seated beside the desk was a man clad in black. His figure seemed unaccountably dim in the gloomy light of the room. He was looking at Doctor Lukens, and the man’s face was vividly strange. An exclamation of astonishment came from the physician as he surveyed the countenance of the visitor.

It was smooth as parchment. It was masklike in its expression. The eyes were obscured by large, heavy-rimmed spectacles which were supplied with dark-tinted glass.

Doctor Lukens had an impression that there were unusual eyes behind those glasses; that the stranger wore them to conceal the vivid sparkle of his eyes.

“Who are you?” demanded the physician.

“You would not know my name,” replied the man in calm, even tones.

“What are you doing here?”

“I have come to see you” — the stranger extended a long, black-clad arm, and his hand rested upon the code — “to see you about this. You are anxious to solve it, I believe?”

“I did not hear you come in,” said Doctor Lukens coldly.

“You were engrossed in your work,” replied the stranger, quietly. “I did not care to disturb you.”

The physician rubbed his forehead with both hands. He realized that he had been under a nervous strain.

He supposed that he had not heard the man ring the bell of the front door.

“Perhaps I have been overtaxing myself,” he admitted. “I remember now that I told Oscar to send up any one who might come to see me about the code.

“I must apologize for being brusque. I have been greatly disappointed, because no one has been able to gain results with the code.”

THE stranger bowed slightly in acceptance of the physician’s explanation. Doctor Lukens handed him the letter that lay at the side of the desk.

“I thought that I had heard from all who received a copy of the code,” said Doctor Lukens. “This is the last letter that I received. It is substantially the same as the others.

“None of the experts have had success. Yet I have been assured that the best minds have been at work upon the code.”

The stranger read the letter. He nodded his head slightly as he perused its contents. He placed the letter upon the desk and stared thoughtfully at Doctor Lukens.

“What is your opinion?” questioned the physician.

“The experts have stated the facts,” the strange man spoke.

“Why, then, have you come to see me?”

“Because I should like to see the original code. I have examined a photostatic copy only. I have formed my opinions. I do not believe that I shall change them. Nevertheless, I should like to see the original.”

Doctor Lukens handed over the required document. The stranger studied it for several minutes while the physician watched him in bewilderment. At last the man with the dark-tinted glasses replaced the code on the desk.

“The photostatic copy is identical,” he said. “That is all I needed to know.”

Something in the man’s tone inspired Doctor Lukens with hope.

“Ah!” exclaimed the physician. “You believe that a solution is possible?”

The stranger shook his head.

“Quite the contrary,” he replied. “Like the others who have examined it, I must say that I can read no message in it. It is not a cryptogram. It is not a numbered code. It does not correspond to any existing system of code making.”

Doctor Lukens sighed in disappointment.

“There are various systems of code,” explained the visitor in his quiet, easy voice, “and all codes are not decipherable. There are certain codes which depend upon artificial languages or vocabularies known only to those who have prepared them. Such codes are virtually unsolvable.

“I have examined many codes. In every one I have at least found a clew to the system involved. I have met with systems that are apparently new; yet in each instance they have borne some similarity to an existing type of code.

“The experts to whom you have sent copies of this code have doubtless had experiences similar to mine. Therefore I concur with their decisions — but I must add a statement of my own.”

Doctor Lukens listened intently. The stranger did not speak for a moment. He was thinking, about to phrase an important statement.

“The experts,” resumed the stranger, “say that they can not solve the code. Do they say that it is impossible to solve the code?”

“They have implied it,” returned the physician promptly.

“They are correct in that implication,” said the stranger. “I suppose then that their reason lies in the fact that the system of the code is entirely unique.”

“That is certainly the reason.”

“It is not a good reason. The solution of any code is within the realm of possibility — even though its system is entirely new.”

“Then the code can be solved?” There was sudden hope in Doctor Lukens’ voice.

“No.”

“Why not?”

“A code,” said the man in black, “is a message transcribed into some ingenious system of lettering or characters. Am I correct?”

“Certainly,” agreed Doctor Lukens.

“Then this is not a code!”

“Not a code?”

“No,” replied the stranger with a faint smile. “Even the man who wrote it cannot solve it. It is merely a collection of oddly shaped characters arranged to deceive those who attempt to read it!”