“None of that,” she cried. “You can’t back out now. Besides, we’re only beginning to have some fun.”

“Fun!” groaned Vi, keeping a wary eye on the handkerchief that Laura still held. “Well, I’m glad I know what to call it.”

“Come on,” said Billie, jingling her rusty keys and starting up the ladder. “Now we’ll see whether one of these keys will fit.”

“I hope it doesn’t,” said Vi, under her breath, but Laura caught her up sharply.

“What did you say?” she demanded.

“Oh—nothing,” said Vi.

By this time Billie was on the top rung of the ladder and her fingers trembled as she tried to fit the first of the keys into the lock. She had more courage than Vi, yet almost she echoed the other girl’s wish—that she would not be able to find a key to fit.

She wanted to see what was on the other side of that locked door, yet for some reason—perhaps the blood-stained handkerchief—she was afraid to find out.

She had tried every key till she came to the next to the last, while Laura and Vi fidgeted at the foot of the ladder.

“Won’t they fit?” asked Laura, impatiently and in a high-strung tone.