Not in obedience to the summons; but because of a sound and a scent that smote him as he started to gallop away.

An eddy of the wind had borne both to the dog's acute senses.
Stiffening, his curved eyeteeth baring themselves, his hackles bristling, Lad galloped back to the ravine-lip; and stood there sniffing the icy air and growling deep in his throat.

Looking down to the ledge he saw Cyril was no longer its sole occupant.

Crouched at the opening of a crevice, not ten feet from the unseeing child, was something bulky and sinister;--a mere menacing blur against the darker rock.
Crawling home to its lair, supper-less and frantic with hunger, after a day of fruitless hunting through the dead forest world, a giant wildcat had been stirred from its first fitful slumber in the ledge's crevice by the impact of the child upon the heap of leaves.

The human scent had startled the creature and it had slunk farther back into the crevice.
The more so when the bark and inimical odor of a big dog were added to the shattering of the ravine's solitude.
Then the dog had gone away.