Nan's and Ben's absorption in each other's conversation. He and Edith had dropped behind, making spasmodic efforts to talk, but without heart.
They had ridden for an hour or more before they entered the cool gloom which lay between the two great walls, and had splashed for some distance through the rocky creek-bed, when suddenly the horses pricked their ears, and Nan's wheeled, stretching its neck as though to listen.
"How strange!" she exclaimed. "Whoa!"
Ben jerked his horse sharply.
"What's the matter with you!"
"Something's wrong!" declared Edith. "My horse never acts like this. Steady, now!"
Nan's spirited horse tried to bolt. It took all her strength to pull him down.
"They act like they smelled bear or some varmint." Mystified, Ben threw back his head and searched the perpendicular rocks above them. His horse was quivering in every muscle.
Simultaneously the horses reared and plunged, their nostrils distended, their ears
