ten o'clock before
`` I wonder -- '' she said , then , remembering an old rat trap that she had come across several days ago , ran into the pantry to get it . She baited it with a fresh piece of cheese and set it carefully on the piano . `` Now , '' she said , standing back and regarding her work with satisfaction , `` we shall see what we shall see ! '' It was ten o'clock before the girls finally came down , and it was still later before the boys appeared . Mrs. Gilligan and Billie had had breakfast together , and Billie had confided to the older woman her suspicions in regard to the ghostly player of the old piano . `` But we wo n't tell the boys and girls , '' Billie had said , with a delightful sense of conspiracy . `` We 'll wait and see if it works . ''