up, and with one last effort she came out upon an open ledge and
looked about her.

She could not help an exclamation of delight at what she saw. The
rock was so high that they could look out over the treetops clear
to the slope where the little gray house stood. The waterfall,
plunging from a still higher level, made a barrier on one side of
them, and on the other side the cliff rose, a sheer wall of rock.
Between the wall of water and the wall of rock there was a cave
extending into the solid rock for a distance of about twenty
feet. There was absolutely no way of reaching this fastness
except through the hidden stair, and one might wander for years
through the forest and never see it at all.

"Oh," exclaimed Jean, "it's wonderful! How Jock will love this
place! Don't you believe this very cave was used by Rob Roy and
his men?" and Alan, swelling with pride to think he had found it
all himself, said yes, he was sure of it.

"I tell you what we'll do," cried Alan, a minute later. "We'll
just leave the basket here in the cave, and when we've found the
boys we'll come back and have our lunch here."

They tucked the basket away out of sight on a rocky shelf in the
cave, and found their way down the steep rough stairway to the
bed of the stream again and, making a wide detour, came out above
the fall. They struggled on for nearly a mile farther still
without finding any trace of the boys, and were beginning to be
discouraged, when they saw a break in the trees with glimpses of
blue sky beyond, and a few moments later came out upon the shores