Watusk turned to the right.  Presently they were stopped by a bluff of poplar saplings growing in a hollow.  Here all dismounted and tied their horses to trees.

Ambrose’s ankles were loosed and, with an Indian’s hand on either shoulder, he was guided through the grass around the edge of the trees.  He speculated vainly on what this move portended.

No attack, certainly; they were striking matches and lighting their pipes.  Suddenly the dim figures in front were swallowed up.

Immediately afterward Ambrose was led down an incline into a kind of pit.  The smell of turned earth was in his nostrils; he could still see the stars overhead.  They gave him a corner, and his ankles were again tied.

Soon it began to grow light.  Little by little Ambrose made out the confines of the pit or trench.  It was some twenty-five feet long and five feet wide.  When the Indians stood erect, the shortest man could just look over the edge.

Ambrose counted twenty-one men besides Watusk and himself.  It was close quarters.  When it became light enough to see clearly, they lined up in front of him, eagerly looking over.  One was lighting a little fire and putting grass on it to make a smudge.

Ambrose got his feet under him, and managed after several attempts to stand upright.  He was tall enough to look over the heads of the Indians.

Stretching before him he saw the valley he had remarked the evening before, with the streamlet winding like a silver ribbon in a green flounce.

But what the Indians were looking at were little pillars of smoke which ascended at intervals all around the edge of the hills, hung for a moment or two in the motionless air, and disappeared.  Ambrose counted eight besides their own.

Watusk exclaimed in satisfaction, and ordered the fire put out.  This, then, was the explanation of the digging—­rifle-pits!

Ambrose marveled at the cunning with which it had all been contrived.  The excavated earth had been carried somewhere to the rear.

Wild-rose scrub had been cut and replanted in the earth around three sides of the pit, leaving a clear space between the stems for the men to shoot through, with a screen of the crimson leaves above.

So well had it been done that Ambrose could not distinguish the other pits from the patches of wild-rose scrub growing naturally on the hills.

Ambrose’s heart sank with the apprehension of serious danger.  He began to wonder if he and all the other whites in the country had not under-rated these red men.  Where could Watusk have learned his tactics?  The thing was devilishly planned.

With the cross-fire of two hundred rifles they could mow down an army if they could get them inside that valley.  Each narrow entrance was covered by a pair of pits.  Every part of the bowl was within range of every pit.

Ambrose feared that the police, in their careless disdain of the natives, might ride straight into the trap and be lost.