Sid decided three things for himself during the miles that Pinto laid behind them with that tireless gait of the plains mustang. Happiness, for him, lay close to Nature. She was by far the grandest thing in the world, the one thing of which he never tired and of whose wonders there was no end. Others might prefer the intellectual life of cities, where the body was forever weary, forever crying for good, healthy, sweating exercise, even if the mind was kept occupied. To satisfy them both and be a whole man, happy all over with the thrill of good health of mind and body, a life in the open was the only surety. That other life would be surely a misery for his body, caged like a setter dog in a city flat--there would be absolutely no escaping it. For his mind it would mean simply an exchange of interests, working with live things as the raw material instead of with machinery or in spending his days dictating letters, which was the bulk of the “work” done by most of the men he knew. He shrank from such a life as from a plague. Far better to be just reasonably well off, or even poor, than exchange for a heaping measure of dollars everything that gave one joy in living. Life in the open, for him, could be agriculture or mining or ethnology. The human interest of the latter inclined him strongly toward it. It combined idealism with practical, useful work. To make others happy, to help the misunderstood and protect the unjustly treated--that would be a life that could appeal to Sid’s generous, open-handed nature! He had arrived at that point in his reflections and his pony had rounded perhaps the fiftieth of the great red parapets and promontories that crisscrossed ahead of him in the winding valley, when two enormous red walls, flat as masonry and hundreds of feet high came to view across the dry bed of the stream. Sid reined up his pony, looking up at them in wonder, and then at the dim distances beyond with a feeling of utter bewilderment. Surely this was a grim joke that Big John had played on him,--the merciless Arizona humor as practiced on the abysmal tenderfoot! “This must be the Canyon Cheyo, and those huge walls are ‘Los Capitanos del Canyon,’ as the Spanish named them--but where is the entrance?” he asked himself, perplexedly. Then the truth burst upon him. That line of dim gray cliffs, apparently five miles down the valley was the _other wall_ of the Canyon! The whole thing was its mighty gate! “Gee-roo! Things are done on a big scale out here!” exclaimed Sid as he surveyed it, dismayed. “You could drop a whole eastern state in the mouth of this canyon and it would never be missed! No wonder there are whole ruined cities on the floor as well as the walls of Cheyo!” he cried, ruefully, as he began to wonder how his party would ever find _him_ in all this vast expanse of cliff and valley.