was free of that constricting rope, but as he moved forward, groping, just ahead there came to him a sudden murmur of voices, low, like the growling of savage beasts. There was that sort of note in it: A fierce, avid mutter, and presently, as he advanced, he made out here and there a word.
"Th' Big Gun... You better watch your step... Mar—"
Quarrier found himself in a sort of corridor, at the far end of which proceeded the voices. It had all been done in the dark, so to speak. The taxi, that driver with the face familiar and yet unfamiliar, the attack, and now this. But time pressed. Why they had not murdered him out of hand he did not pause to consider; he knew only that Marston—and he was certain that it was Marston's hand that had been in it—would, with a clear field, be at the hiding-place of those documents. Even now, doubtless, he was there.
Quarrier felt mechanically for his pistol; and then his hand dropped hopelessly as he remembered that he was weaponless.
He listened tensely, holding his breath, as the voices receded—or, rather, one of them; he could hear the other following the departing man with his complaints.
Evidently they had left a guard of two. One of them was going; the other left behind, and not especially delighted with his job.
An abrupt turn of the long hallway brought this man suddenly into plain view.
Quarrier blinked in the glare from the single incandescent, flattening himself against the wall; then, with a pantherish space, he had covered the intervening space in three lunging strides.
The man, a broad fellow with a seamed, lead-colored countenance, turned his head; his mouth opened, his hand going to his pocket with a lightning stab of the blunt, hairy fingers.
But Quarrier had wasted no time. Even as the giant reached for his gun Quarrier's fist swung in a short arc, and there was power in it. The blow, traveling a scant six inches, crashed full on the point; the thickset man, his eyes glazing, swayed, slipped, fell in an aimless huddle.
"Well—a knockout!" panted Quarrier, reaching for the pistol.
Marston was the "Big Gun", of course. Quarrier had never doubted it; but hitherto the President of Intervale Steel had conducted his brokerage business, on the surface at any rate, without resort to open violence. And Intervale Steel—You knew really nothing about it until you took a flyer in it; then, as it might chance, you knew enough and more than enough.
Quarrier, glancing at the unconscious man and pocketing the pistol, departed without more ado; proceeding along the hall, he found, with no further adventure, a narrow door, and the pale stars, winking at him from, he judged, a midnight horizon.
But a glance at his watch told him that it was but nine-thirty; there was yet time to get to the hiding-place of those documents ahead of Marston, if, as he was now convinced, it had been Marston's thugs who had ambushed him.
Plunging along the shadowy alley, after five minutes' walk, made at a racing gait, he found a main-traveled avenue and an owl taxi, whose driver, leaning outward, crooked a finger in invitation to this obvious fare, appearing out of the dark.
Quarrier did not hesitate. The fellow might be a gunman or worse; he must take his chance of that.
"Twenty-three Jones!" he called crisply, with the words diving into the cab's interior; then his head out of the window, as the taxi turned outward from the curb.
"And drive as if all hell were after you!"
III.
The Shape Invisible.
Quarrier reached his destination without incident, but as he went up the winding stairway of the office building to his private sanctum he was oppressed by an uneasy sense that all
