“What’s the big idea?” gasped Laura, as they ran together down the hall toward the dormitory. “What do you expect to do to poor Nick—sandbag him?”

“Something like that,” returned Billie, slipping hurriedly into her coat and hat and motioning impatiently for the girls to do the same. “If we can only get hold of him we may be able to frighten him into telling us where the machinery is.”

“Oh, and maybe I’ll be able to get my watch back!” added Connie, pulling a dark cap down over her fluffy hair and carefully adjusting it at the right angle.

“We won’t get anything if you don’t hurry,” said Billie, regarding her impatiently. “What do you think you’re going to, anyway? A party?”

“You had better put on your leggings,” suggested Vi, looking doubtfully at the rubbers Billie had pulled on over her shoes. “The snow’s awfully deep.”

“Haven’t time,” cried Billie, adding distractedly: “For mercy sake, hurry! While you girls are dolling up for a party, Nick Budd will be gone.”

At this dreadful thought the girls stopped fussing and followed Billie hurriedly down the stairs. They slowed down in the lower hall, however, for there they were apt to meet a teacher, and undue haste might be thought suspicious by one of these “unreasonable beings.”

At sight of Nick Budd, a plan had come to Billie. She remembered how terrified he had seemed when he had found Teddy and her in the cave that day and thought in his crazy mind that they had come to arrest him.

So she was going to take a chance of so frightening him with a threat of arrest that he would confess, and perhaps even be prevailed upon to lead them to the cave.

In case this plan should fail, she had not an idea in the world what she would do next. But the plan did not fail. It worked more perfectly than she had dared to hope.