Then came the dull thud when the leaden ball beat itself shapeless against the stone wall beside him.

The bullet had passed within an inch of Nick’s ribs, and he knew at once that he was now a mark for hidden foes.

Yet there had been no revolver report to suggest their location, and Nick instantly surmised that the ball must have been discharged with an air gun.

He knew that it must have come from some quarter behind him, however.  And he knew, too, how to bring his murderous assailants from their secret cover.

As quick as a flash, the instant the ball smote the wall beside him, Nick let go his hold upon the stone coping and dropped into the darkness below the window, falling prostrate upon his back.

As he lay there his hand touched something hot, and he drew it nearer to examine it.

It was the battered chunk of lead which had come within an inch of ending his life.

“They meant business, for sure,” he said to himself, while waiting for his quick-witted ruse to operate.  “I’m blessed if this affair is not taking on a new and lively interest.  I reckon there’ll be more doing to-night than I gave Patsy to believe.

“Ha, ha!  The scoundrels are already breaking cover!”

His alert ears had detected a sound from the direction of the stable, and now he silently drew his revolver and held it gripped by his side.

Presently the stable door was cautiously opened.  Then a momentary beam of light, evidently from a bull’s-eye lantern, shot across the paved area, and lingered for an instant upon Nick’s prostrate figure.

Nick remained as motionless as a corpse.

Then two men, both large and powerful fellows, and both heavily bearded, came quickly from the stable and hastened toward him.

“Done for with a single shot,” remarked one, as they approached.

“Looks like it, Dave,” was the reply.  “When I piped his head in the light from the window, I felt sure I could drop him.”

“Well done.  ’Twas a good shot.  Shove your hand inside his vest, and see if his heart is beating.  Then we shall know for sure whether he’s down and out.  If not, we must—­”

“Throw up your hands, instead, both of you!” Nick sternly interrupted, half rising with weapon leveled.  “At the first move by either, I will shoot to kill!”

Nick had foreseen that his foxy strategy must be very quickly detected, and he had resolved to take the bull by the horns, and attempt to arrest both of his cowardly assailants.

That he was up against uncommon men, however, men of extraordinary nerve and reckless daring, appeared in what instantly followed, even under the very muzzle of the detective’s revolver.

As quick as a flash, before Nick’s threatening command was fairly out of his mouth, the man called Dave made a kick at the detective’s uplifted arm, so swift and accurate and forceful that Nick felt the bones of his wrist fairly crack under the blow, and the fingers of his hand gripping the weapon turned numb and tingling as if from an electric shock.