and came rattling and bounding down the canyon face. Every
nerve in Linda tensed. She opened her mouth, but not a sound came. For a
breathless second she was paralyzed. Then she shrieked wildly: "Donald,
Donald, roll under the ledge! Quick, quick!"

She turned to Katy.

"Back, Katy, back!" she screamed. "That boulder is loose; it's coming
down!"

For months Donald Whiting had obeyed Linda implicitly and instantly. He
had moved with almost invisible speed at her warning many times before.
Sometimes it had been a venomous snake, sometimes a yucca bayonet,
sometimes poison vines, again unsafe footing--in each case instant
obedience had been the rule. He did hot "question why" at her warning;
he instantly did as he was told. He, too, had noticed the falling
pebble. With all the agility of which he was capable he rolled under
the narrow projecting ledge above him. Katherine O'Donovan was a good
soldier also. She whirled and ran to the roadway. She had barely reached
it when, with a grinding crash, down came the huge boulder, carrying
bushes, smaller rocks, sand, and debris with it. On account of its
weight it fell straight, struck heavily, and buried itself in the earth
exactly on the spot upon which Donald had been lying. Linda raised
terrified eyes to the top of the wall. For one instant a dark object
peered over it and then drew back. Without thought for herself Linda
rushed to the boulder, and kneeling, tried to see back of it.

"Donald!" she cried, "Donald, are you all right?"

"Guess I am, unless it hit one foot pretty hard. Feels fast."

"Can you get out?" she cried, beginning to tear with her hands at the
stone and the bushes where she thought his head would be.

"I'm fast; but I'm all right," he panted. "Why the devil did that thing
hang there for ages, and then come down on me today?"

"Yes, why did it?" gasped Linda. "Donald, I must leave you a minute.
I've got to know if I saw a head peer over just as that stone came
down."

"Be careful what you do!" he cried after her.

Linda sprang to her feet and rushed to the car. She caught out the field
classes and threw the strap over her head as she raced to the far side
of the fireplace where the walls were not so sheer. Katherine O'Donovan
promptly seized the axe, caught its carrying strap lying beside it,
thrust the handle through, swung it over her own head, dropped it
between her shoulders, and ripping off her dress skirt she started up
the cliff after Li