and nearing the ridge along which he had previously
followed the tracks of the two horsemen. With the knowledge he had
gained how the track turned and twisted, he set his horse to the rising
ground, and rode steadily and cautiously until he arrived at the summit
of the steep immediately above where the creek entered the pool.

Below him was the narrow sandy strip running round the edge of the
water, and even from where he was he could see the marks of the horses'
hoofs upon it. His glance wandered from the shore over the surface of
the pool. It was a long sheet of water, more an exaggerated reach in a
stream than a lake, for except along the sandy margin below him, the
water everywhere rippled right up to the dense verdure-clad slopes of
the hills.

A curious discolouration appeared in a streak across the pool at the
far end. The otherwise clear water was marred by a ledge of rock which
stretched from one side of the pool to the other and came so near the
surface as to give a suggestion of muddiness to the water.

Dismounting, he led his horse to a sheltered gully, and securely
tethered him to a tree. Then, with his carbine on his arm and his
revolver pouch unfastened, he walked down to the dry bed of the creek
and followed it to the mouth.

Fresh marks were on the soft ground near the water, coming from the end
of the pool where the streak of muddy water showed, and passing onwards
round the pool. He decided to go in the same direction, and for a few
yards walked along the level before he discovered other hoof-prints,
equally clear, going the opposite way. The horseman, whoever he might
be, had both come and gone within the past few hours, but Durham was
uncertain which way had been the last.

Leaving the level ground he forced a way through the thick herbage
growing on the bank above and crept forward. As he went he obtained
through the foliage an occasional glimpse of the track below, until the
bank rose so steeply and the vegetation became so dense that he had to
climb higher to move along at all. Presently he came to an easier grade,
and was able to see once more the margin of the pool, but he was
surprised to discover that all marks of the horses had ceased.

He crept down to the water. Looking back, he saw that the bank, on the
top of which he had been, ran out to the water's edge, forming a
barrier across the track and terminating in a steep bluff jutting out
into the pool.

Crouching almost to the groun