“O, _you_, Cathalina,” said Isabel, “you aren’t a bit like her. _Your_ face is sweet and hers isn’t.” Cathalina then told of her experience in the reception room. “We must be nice, anyway, and as good to her as possible, as she’ll let us be. I have a funny feeling that I’ve seen her somewhere or some one with the same features, but I can’t remember.” “Who’s her roommate?” “She is in the single room on the first floor, around at the end of the corridor running west from Miss Randolph’s rooms. She just goes around with her head in the air that way all the time, I guess, and unless she gets over it she’ll not make many friends.” “Well, let’s speak to her when she’ll let us. I have an idea that she’ll change after a while. I introduced myself, but she did not tell me her name. Do any of you know what it is?” Nobody did. “The Mysterious Girl of Single Room Number Blank! Betty, here’s our title for that story we have to write in English.” Betty had hardly said a word during this conversation, but now remarked, “I suppose there are girls here with queer stories in their lives. If we knew them we’d learn a whole lot.” “Yes; maybe it’s just as well we don’t. But I guess Miss Randolph is very careful about what girls come here. Aunt Knickerbocker said so.” This, Isabel declared, was mystery number one at Greycliff and what was a boarding school without _some_ mystery? To mystery number two she was introduced that night, by no desire of her own. The Hall was wrapped in slumber, usually quite profound, for while the girls often grumbled about putting out lights on time, they slept soundly and morning came all too soon. But about midnight Cathalina and Hilary were wakened by a loud shriek that reverberated through the halls and was followed by another; then, silence. Both frightened girls sat up in bed and by one impulse slipped into bath robes and slippers and opened their door, peering out, half afraid but curious, in the corridor. This was dark, lighted only by one dim gas light at the further end. But they could see Avalon’s ghostly face at her half open door and Isabel leaning against the wall not far away, her face hidden in her arm. She was shaking all over. “Sh-sh!” said Avalon, her first thought of the teachers. “What on earth’s the matter?” asked Hilary in a low voice. “Somebody was screaming to beat the band!” “O,” gasped Isabel, as she heard Hilary’s voice, and ran with open arms toward the two girls. “I was just scared to death,” she whispered. “O, I’ll not sleep one wink this night!” Cathalina went on toward Avalon, whom she found trembling with fright. “Come over to our room and tell us what the trouble was. Who screamed?” “Isabel!”