The boy ranchers rode leisurely along, for there was no special hurry in getting back. It might reasonably be supposed that the rustlers would not again make a raid within a few days at least. And Old Billee, Yellin' Kid, Snake Purdee and Four Eyes, to say nothing of Buck Tooth, were well able to look after matters in Happy Valley. And thus proceeding at a foot pace, it was well after midnight when the boys started down the last slope that led into the valley proper. In daylight it would have been possible, from this part of the trail, to have observed the tents and the reservoir. But now all was shrouded in darkness. No, not altogether darkness, for as the boys rode forward there suddenly glimmered in the gloom a light, high up in the air. At first Bud thought it was a star, but a moment later as it moved from side to side, and then up and down, he exclaimed: "Look, fellows! A signal!" "Signal!" repeated Dick. "Yes. Over at our camp! See! There's a light on our watch tower." "Maybe there's been another raid!" said Nort. "Or going to be one!" spoke Bud, grimly. CHAPTER XIV FOUR EYES--NO EYES Thudding along, their ponies seemingly as eager to reach the ranch camp as were the boys themselves, Bud, Nort and Dick raced toward the mysterious light. For that it was mysterious they all agreed, and that it was flashing from the top of the watch tower they had built to spy for rustlers was another conclusion. "Do you s'pose it can be Old Billee, or Yellin' Kid signalling to us?" asked Nort, as he galloped between Bud and Dick. "They wouldn't know we were coming," Bud answered. "I said we might not be back until to-morrow." "That's so. But who do you think is signalling?" asked Dick. "And who are they signalling to?" Nort wanted to know. "That's what we've got to find out," spoke Bud, grimly. "And it's what we're going to find out in a short time! Come on, Sock!" he called to his pony. "This is only exercise for you!" Indeed the animals had not been hard pressed, and this burst of speed was rather a relief than anything else. Together the boy ranchers hastened toward their camp. For some time the lantern--it was evidently that and not a torch--was waved to and fro, parallel to the horizon, and again up and down. It was so evidently a signal, or a series of them, that the boys no longer questioned this theory. But who the signaller was, and to whom he was flashing his message in the dark night--those were other questions. And they were questions that needed answering. "It must be one of our men," remarked Bud. "No one else could get into camp and climb the tower without a row being raised." "How do you know there hasn't been a row?" asked Dick. "What do you mean?" countered Bud.