The gray adobe building where the unmarried office men and engineers lived was gay with colored lights and cedar festoons. The hall in the rear of the building had an excellent dancing floor. The orchestra was composed of three Mexicans--hombres--with mandolins and a guitar, and an Irish rough-neck who brought from the piano a beauty of melody that was like a memory of the Sod. The four men produced dance music that New York might have envied. Several Cabillo couples attended the dance. Oscar Ames and Jane and one or two other ranchers and their wives were there. All the wives of the officers' camp came and the bachelors searched both the upper and lower camps for partners, with some very charming results. Mrs. Flynn sat with Sara, and Jim insisted that instead of going with Jane and Oscar, as she had planned, that he be allowed to take Pen to the first ball she had attended since her marriage. Henderson had ordered that the costumes be kept a great secret. Through a Los Angeles firm he provided dominoes for the five committeemen. But there were half a dozen other dominoes at the ball, so the committee quickly lost its identity. Oscar Ames came as a hobo. Henderson had a policeman's uniform, while the two cub engineers wore, one, a cowboy outfit; the other, an Indian chief's. Mrs. Henderson was dressed as a squaw. Penelope wore a flower girl's costume, improvised from the remains of the chintz she had brought from New York. Jim viewed her with great complaisance. No one could look like Pen, he thought, and he would dance with her all the evening. Jim went as a monk. To his chagrin, when they reached the hall he found that Pen had made Mrs. Ames a costume exactly like her own, and with the complete face masks they wore, they might have been twins. They were just of a height and Mrs. Ames danced well. The children and the phonograph had long ago attended to that. There was nothing stupid about the ball from the very start. The policeman ended the grand march by arresting the hobo, who put up a fight that included two of the dominoes. The orchestra swung into "La Paloma" and in a moment the hall was full of swaying colors, drifting through the golden desert dust that filled the room. There were twice as many men at the ball as women. The latter were popular to the point of utter exhaustion. Henderson looked over the tallest domino, seized him by the throat and with wild flourishes of his club, backed him into a corner. "Say, Boss Still Jim," he whispered, "that old nut of a chairman doesn't look as if he had anything but skim milk in his veins. But do you sabez he's danced three times with that little fat ballet girl and he's hugging the daylights out of her. He'd ought to be investigated." The tall domino looked at the couple indicated. "I'll start investigating, myself," he whispered.