he
thought of it the more puzzled he became. And then, in a flash, the
possible solution of it all came to him.

Had Culver Rann discovered the secret mission on which he and the old
mountaineer were going into the North? Had he learned of the gold--where it
was to be found? And was their assassination the first step in a plot to
secure possession of the treasure?

The blood in Aldous' veins ran faster. He gripped his pistol harder. More
closely he looked into the moonlit gloom of the trail ahead of him. He
believed that he had guessed the meaning of MacDonald's warning. It was the
gold! More than once thought of the yellow treasure far up in the North had
thrilled him, but never as it thrilled him now. Was the old tragedy of it
to be lived over again? Was it again to play its part in a terrible drama
of men's lives, as it had played it more than forty years ago? The gold!
The gold that for nearly half a century had lain with the bones of its
dead, alone with its terrible secret, alone until Donald MacDonald had
found it again! He had not told Joanne the story of it, the appalling and
almost unbelievable tragedy of it. He had meant to do so. But they had
talked of other things. He had meant to tell her that it was not the gold
itself that was luring him far to the north--that it was not the gold alone
that was taking Donald MacDonald back to it.

And now, as he stood for a moment listening to the low sweep of the wind in
the spruce-tops, it seemed to him that the night was filled with whispering
voices of that long-ago--and he shivered, and held his breath. A cloud had
drifted under the moon. For a few moments it was pitch dark. The fingers of
his hand dug into the rough bark of a spruce. He did not move. It was then
that he heard something above the caressing rustle of the wind in the
spruce-tops.

It came to him faintly, from full half a mile deeper in the black forest
that reached down to the bank of the Frazer. It was the night call of an
owl--one of the big gray owls that turned white as the snow in winter.
Mentally he counted the notes in the call. One, two, three, _four_--and a
flood of relief swept over him. It was MacDonald. They had used that signal
in their hunting, when they had wished to locate each other without
frightening game. Always there were three notes in the big gray owl's
quavering cry. The fourth was human. He put his hands to his mouth and sent
back an answer, emphasizing the fourth note. The