They ran across the shining sand, the Pacific thundering its long surge at their backs, and when they gained the roadway leaped upon bicycles and dived at faster pace into the green avenues of the park. There were three of them, three boys, in as many bright-colored sweaters, and they "scorched" along the cycle-path as dangerously near the speed-limit as is the custom of boys in bright-colored sweaters to go. They may have exceeded the speed-limit. A mounted park policeman thought so, but was not sure, and contented himself with cautioning them as they flashed by. They acknowledged the warning promptly, and on the next turn of the path as promptly forgot it, which is also a custom of boys in bright-colored sweaters. Shooting out through the entrance to Golden Gate Park, they turned into San Francisco, and took the long sweep of the descending hills at a rate that caused pedestrians to turn and watch them anxiously. Through the city streets the bright sweaters flew, turning and twisting to escape climbing the steeper hills, and, when the steep hills were unavoidable, doing stunts to see which would first gain the top. The boy who more often hit up the pace, led the scorching, and instituted the stunts was called Joe by his companions. It was "follow the leader," and he led, the merriest and boldest in the bunch. But as they pedaled into the Western Addition, among the large and comfortable residences, his laughter became less loud and frequent, and he unconsciously lagged in the rear. At Laguna and Vallejo streets his companions turned off to the right. "So long, Fred," he called as he turned his wheel to the left. "So long, Charley." "See you to-night!" they called back. "No--I can't come," he answered. "Aw, come on," they begged. "No, I've got to dig.--So long!" As he went on alone, his face grew grave and a vague worry came into his eyes. He began resolutely to whistle, but this dwindled away till it was a thin and very subdued little sound, which ceased altogether as he rode up the driveway to a large two-storied house. "Oh, Joe!" He hesitated before the door to the library. Bessie was there, he knew, studiously working up her lessons. She must be nearly through with them, too, for she was always done before dinner, and dinner could not be many minutes away. As for his lessons, they were as yet untouched. The thought made him angry. It was bad enough to have one's sister--and two years younger at that--in the same grade, but to have her continually head and shoulders above him in scholarship was a most intolerable thing. Not that he was dull. No one knew better than himself that he was not dull. But somehow--he did not quite know how--his mind was on other things and he was usually unprepared. "Joe--please come here." There was the slightest possible plaintive note in her voice this time. "Well?" he said, thrusting aside the portière with an impetuous movement.