For close upon an hour Robert Cairn sat at his writing-table, endeavouring to puzzle out a solution to the mystery of Ferrara's motive. His reflections served only to confuse his mind.  
A tangible clue lay upon the table before him—the silken cord. But it was a clue of such a nature that, whatever deductions an expert detective might have based upon it, Robert Cairn could base none. Dusk was not far off, and he knew that his nerves were not what they had been before those events which had led to his Egyptian journey. He was back in his own chamber—scene of one gruesome outrage in Ferrara's unholy campaign; for darkness is the ally of crime, and it had always been in the darkness that Ferrara's activities had most fearfully manifested themselves.
 
What was that?
 
Cairn ran to the window, and, leaning out, looked down into the court below. He could have sworn that a voice—a voice possessing a strange music, a husky music, wholly hateful—had called him by name. But at the moment the court was deserted, for it was already past the hour at which members of the legal fraternity desert their business premises to hasten homewards. Shadows were creeping under the quaint old archways; shadows were draping the ancient walls. And there was something in the aspect of the place which reminded him of a quadrangle at Oxford, across which, upon a certain fateful evening, he and another had watched the red light rising and falling in Antony Ferrara's rooms.
 
Clearly his imagination was playing him tricks; and against this he knew full well that he must guard
[175]
himself. The light in his rooms was growing dim, but instinctively his gaze sought out and found the mysterious silken cord amid the litter on the table. He contemplated the telephone, but since he had left a message for his father, he knew that the latter would ring him up directly he returned.
 
Work, he thought, should be the likeliest antidote to the poisonous thoughts which oppressed his mind, and again he seated himself at the table and opened his notes before him. The silken rope lay close to his left hand, but he did not touch it. He was about to switch on the reading lamp, for it was now too dark to write, when his mind wandered off along another channel of reflection. He found himself picturing Myra as she had looked the last time that he had seen her.
 
She was seated in Mr. Saunderson's garden, still pale from her dreadful illness, but beautiful—more beautiful in the eyes of Robert Cairn than any other woman in the world. The breeze was blowing her rebellious curls across her eyes—eyes bright with a happiness which he loved to see.
 
Her cheeks were paler than they were wont to be, and the sweet lips had lost something of their firmness. She wore a short cloak, and a wide-brimmed hat, unfashionable, but becoming. No one but Myra could successfully have worn that hat, he thought.
 
Wrapt in such lover-like memories, he forgot that he had sat down to write—forgot that he held a pen in his hand—and that this same hand had been outstretched to ignite the lamp.
 
When he ultimately awoke again to the hard facts of his lonely environment, he also awoke to a singular circumstance; he made the acquaintance of a strange phenomenon.
 
He had been writing unconsciously!
 
And this was what he had written:
 
"Robert Cairn—renounce your pursuit of me, and renounce Myra; or to-night—" The sentence was unfinished.
 
Momentarily, he stared at the words, endeavouring to persuade himself that he had written them
[176]
consciously, in idle mood. But some voice within gave him the lie; so that with a suppressed groan he muttered aloud:
 
"It has begun!"
 
Almost as he spoke there came a sound, from the passage outside, that led him to slide his hand across the table—and to seize his revolver.
 
The visible presence of the little weapon reassured him; and, as a further sedative, he resorted to tobacco, filled and lighted his pipe, and leant back in the chair, blowing smoke rings towards the closed door.
 
He listened intently—and heard the sound again.
 
It was a soft hiss!
 
And now, he thought he could detect another noise—as of some creature dragging its body along the floor.
 
"A lizard!" he thought; and a memory of the basilisk eyes of Antony Ferrara came to him.
 
Both the sounds seemed to come slowly nearer and nearer—the dragging thing being evidently responsible for the hissing; until Cairn decided that the creature must be immediately outside the door.
 
Revolver in hand, he leapt across the room, and threw the door open.
 
The red carpet, to right and left, was innocent of reptiles!
 
Perhaps the creaking of the revolving chair, as he had prepared to quit it, had frightened the thing. With the idea before him, he systematically searched all the rooms into which it might have gone.
 
His search was unavailing; the mysterious reptile was not to be found.
 
Returning again to the study he seated himself behind the table, facing the door—which he left ajar.
 
Ten minutes passed in silence—only broken by the dim murmur of the distant traffic.
 
He had almost persuaded himself that his imagination—quickened by the atmosphere of mystery and horror wherein he had recently moved—was responsible for the hiss, when a new sound came to confute his reasoning.
 
The people occupying the chambers below were moving about so that their footsteps were faintly audible;
[177]
but, above these dim footsteps, a rustling—vague, indefinite, demonstrated itself. As in the case of the hiss, it proceeded from the passage.
 
A light burnt inside the outer door, and this, as Cairn knew, must cast a shadow before any thing—or person—approaching the room.
 
Sssf! ssf!—came, like the rustle of light draperies.
 
The nervous suspense was almost unbearable. He waited.
 
What was creeping, slowly, cautiously, towards the open door?
 
Cairn toyed with the trigger of his revolver.
 
"The arts of the West shall try conclusions with those of the East," he said.
 
A shadow!...
 
Inch upon inch it grew—creeping across the door, until it covered all the threshold visible.
 
Someone was about to appear.
 
He raised the revolver.
 
The shadow moved along.
 
Cairn saw the tail of it creep past the door, until no shadow was there!
 
The shadow had come—and gone ... but there was no substance!
 
"I am going mad!"
 
The words forced themselves to his lips. He rested his chin upon his hands and clenched his teeth grimly. Did the horrors of insanity stare him in the face!
 
From that recent illness in London—when his nervous system had collapsed, utterly—despite his stay in Egypt he had never fully recovered. "A month will see you fit again,&qu............