"I knew she was unhappy," replied Bertha, in a curiously hard tone. "She's been miserable ever since she's been back. I don't know what made her make up her mind, but she told me she wished she could run away home. I told her not to be silly and that I shouldn't hear of such a thing. I meant to see she didn't get any pretext for permission to go into town. Then, as she says here, one of the weekly boarders told her she knew this part of the country, and you were going not far from her home, at Frattenton, and Frattenton's on the main line for _our_ home--no changing." "Where exactly is this place, Frattenton?" asked Duane quickly. "The other side of the downs--four or five miles away. The road to it runs right over the downs." "And it's the nearest railway station from here?" "Yes." During the couple of minutes taken by this hurried conversation, Kitty had stood silent, listening, not knowing what was really the matter, but gathering that it was something serious. Neither offered to show her the note; she realized that there was some mystery about it that Duane and Bertha both knew all about, but that they did not wish to share with anyone else. She did not ask any questions, but waited to see what would be required of her. Duane turned to her. "Erica's gone," she explained. "She's run away home. She's slipped off across the downs to Frattenton, to the railway station there." Kitty nodded. "What's to be done?" she said curtly. "I don't like the look of those downs. There's a heavy mist coming on and it's already getting dark." "Let's hope she's there by now then," said Duane. "Look here, two of us had better ride after her, and the third one return to school and let Prinny know what's up." "Who's to go back?" asked Bertha. "You had better," answered Duane, speaking in decisive tones for once. "You're done up already with scorching so hard, I can see, and you've got no lamps. Kitty and I are fresh. That is to say, if Kitty doesn't mind a tiring ride now." "I'm on," said Kitty briefly. "Then we'll make a start. Cheer up, Bertha. We'll see she's safe somewhere or other and find out what's happened to her, all right." "I know you will." Bertha tried to muster up a smile as she turned her bike round. "You're a sport if ever there was one, Duane." The next instant she had disappeared round the bend, and Duane and Kitty were left alone again, this time with a feeling of responsibility resting heavily upon them. "Better just ask about the road, at the farm," suggested Kitty sensibly. "We neither of us know it." A few brief questions elucidated the information that the road wound over the downs to Frattenton, that it was a lonely road, but that there were few turnings of any importance, and then one had to keep to the left. The two girls mounted and sped off, determined to cover the greater part of the way before darkness settled down.