At one side of the hall was a baize-covered swing door leading into a passage, at the end of which Mr. Marsh's study was situated. Polly pushed open the swing door, and a minute later she stood on the threshold of the study. There was nobody in the room, and closing the door she turned her attention to the tall clock, which, as has already been said, stood against the wall near the writing-table. With fingers trembling with eagerness, the little girl opened the door of the oak case of the clock and peeped inside.

"There's heaps of room for me," she reflected triumphantly as she scrutinised the swinging pendulum and the heavy iron weights of the old time-piece. "It will be a splendid hiding-place. I am sure I can get in, and if I do stop the clock I can easily set it going again. The boys will never think of looking for me here. But I must hurry."

It was not so easy to get into the case of the clock as she had anticipated it would be, for the door was nearly two feet from the ground, but she succeeded in effecting the feat; and, once inside, she found she could stand upright, though she was obliged to keep in one position owing to the narrowness of the case. She laughed softly to herself as she stood there, listening, ready to shut the door of her hiding-place the minute she should hear sounds of anyone approaching the room. Thus she waited several minutes; but, before very long, the silence was broken by Edgar's voice in the passage, saying:

"I don't suppose she's in the study, but we'll have a look. I expect she's upstairs in the attics somewhere. We must be sharp or she'll manage to get 'home.'"

Polly smiled to herself and hastily drew the door of the clock case close. It shut with a "click," and she was in complete darkness. She heard the boys making a hasty search of the room, then followed the sound of a door slammed, retreating footsteps, and after that complete silence. The searchers had never thought of looking inside the case of the old clock.

"What a famous joke!" thought Polly delightedly. "Now, whilst they're in the attics I'll slip back to the schoolroom. I shall be on the laughing side this time."

But she was not so sanguine on that point when, having allowed a few minutes to elapse, she tried to push open the door of her hiding-place, for to her dismay it would not move. Then it dawned upon her that she had made herself a prisoner. Evidently the clock case could only be opened from the outside.

At first the little girl was more vexed than startled at her situation as she reflected that her cousin and brother would make merry over it, and it was not until she had shouted again and again and, knocked loudly, without bringing anyone to her assistance, that she began to experience a distinct sense of alarm; but even then she was not very frightened, for she felt certain her uncle would visit his study on his return from business, he would doubtless have letters to write, so she consoled herself with the hope that she would not be a prisoner very long.

The minutes dragged slowly on, and Polly began to wonder if there were spiders in the clock, or perhaps earwigs—she had a great horror of earwigs. She had noticed that the inside of the case was very dusty, as though it might harbour all sorts of creepy, crawly things; and suddenly she thought she felt something on her neck, and uttered a cry of fright. It proved to be only her imagination, however.

"Oh, this is terrible!" she exclaimed, now thoroughly alarmed. "I'm getting so hot, I believe I shall be suffocated. Oh, will nobody come to let me out! Roger! Roger!" And she beat against the door of the clock case with her hand; then listened, but not a sound was to be heard.