The Motor Maids had begun to learn by this time that it was invariably Mr. Campbell's way to leave his guests in a cheerful frame of mind, and they all knew perfectly well that "Rules for Sunrise Camp" had been prepared chiefly for Billie's sake, that she would be still laughing when her father kissed her good-by and still smiling when he turned to wave his hat for the last time. She had been very homesick for him lately during his absences from West Haven, perhaps because she had been run down in health and tired out. And to-day, in spite of all the laughing and joking, her eyes filled with tears as she watched the car creep down the mountain road to the valley. For a little while the camp seemed lonely and remote. "The truth is," thought Mary, wandering down the path to look at the view, "Mr. Campbell is so splendid that when he goes away he always leaves a big empty space that doesn't seem to fill up. And Billie is just like him. Nobody ever could fill the emptiness she would leave." As if drawn by these loyal and devoted thoughts, Billie had followed Mary, and the two girls stood with clasped hands watching the distant motor, now a black speck in the valley. "Dearest, dearest Papa," exclaimed Billie under her breath, as the tears welled into her eyes and slipped down her cheeks. Mary pressed close to her side with silent sympathy. Presently Billie wiped her eyes and began to smile. "Don't tell on me, Mary dear. I'm just like a foolish little girl. But I do love Papa so, and sometimes I can't bear to have him leave me. Then I wish I had been born his twin brother and we never could be separated." Mary was about to dispute this argument on the grounds that marriage would have separated them, when they noticed coming up the steep road a small bony horse drawing a little cart. A girl was walking at one side, holding the reins. She wore a broad-brimmed jimmy hat and an old gingham dress faded to a soft mellowed pink. The two girls watched her with admiration as she swung along the road, swaying slightly at the waist like one who had adopted the easiest way of walking up hill. They were so intent upon her that they hardly noticed the blackberries and vegetables in the back of the cart. Presently the girl paused and turned her beautiful dark blue eyes on them without any embarrassment. "Want to buy any vegetables?" she asked. "Perhaps they will up at the camp," said Billie. "Ask Mrs. Lupo." The mountain girl looked at her strangely and shook her head. "Do you know Mrs. Lupo?" asked Billie. "Yes, but I will not ask her." "Very well, I'll buy something myself. What have you got?" "Blackberries, onions and beets." Billie bought a pail of berries. "You had better come up to the camp and let me empty them," she said. "Keep the pail," answered the mountain girl, and swung on up the road, flicking the little old horse with a long switch.