Shepherds of the Wild by Edison Marshall — Read

It was more than a reprieve -- the little hour that they would have together before their own island was submerged. They were three shepherds, and in their united strength they were not so fearful of such stars as would be borne into their sky. Here was comradeship instead of loneliness, courage instead of terror, and the deathless joy of love instead of despair.

They went, the three of them, back to the motionless flock. In the first place the sheep were fairly in the center of the space of unburned forest -- a brushy hollow where the smoke was least -- moving just enough to keep halfway between the steadily advancing fire upwind and the slow-creeping backfire in the opposite direction. Besides, they were shepherds, and in their own hearts they felt a blind but undeniable satisfaction in being with the flocks at the end.