The bullet rent a splintering hole in the porch roof. The marksman, in his staggering retreat, slipped off the edge of the top step and bumped backward to earth; with a thud that knocked the breath out of him.

Scarce had his lean shoulders touched ground when Treve was on him; ravening for his throat.

Mack watched, dumbfounded. Joel, quicker-witted, yelled to the dog. Reluctantly, Treve quitted his prey; and in a bound was back at Joel’s side; while Royce Mack with profuse apologies was helping the sputteringly infuriated Hibben to his feet.

Joel surreptitiously picked up the fallen pistol from the floor and pocketed it. Then he turned to look at Treve, who had left his side and had moved across to Nellie.

The puppy, frightened out of all self-control, had bolted. Her blundering rush had brought her up against the house door with a force that knocked her down. Now, shaking all over and moaning softly, she crouched with her head hidden in the angle of porch and door.

Above her stood Treve; his eyes fixed on Hibben in cold menace. The big dog knew well that it was not permissible to attack a human; least of all a human who was the guest of his two masters. Perhaps swift death might be the punishment for his deed. But he did not falter.

His body shielding the wretched puppy, he stood there, tensely ready for Hibben’s next assault. Joel Fenno read the dog’s purpose and his thoughts; as he might have read those of a fellowman. The collie was playing with possible death, to guard something that could not defend itself. Fenno’s gnarled old heart gave a queer twist.

“Trevy!” he breathed, under cover of Hibben’s loudly truculent return to the porch.

At sound of Joel’s voice, Treve shifted his stern gaze from Chris to the old man. And in the collie’s sorrowful dark eyes, now, was an agony of appeal. So might the eyes of a mother be raised to the doctor who alone could save her sick child.