“If I go, will you promise faithfully not to get out of bed for a single minute till I come back?” Maud nodded emphatically. “I’ll promise, cross my heart, and that’s the solemnest promise anybody can make, and if you break it something awful will happen to you. Mary told me it would. I’ll lie just as still, as still, and when you come back you can tell me all about the singing lady.” “And will you gargle and take your powders all day without making any more fuss?” “Yes, and I’ll give you my best paper doll, and all her dresses. Don’t you think I’m kind?” Molly moved slowly towards the door. “It seems an awful thing to do,” she said, “but I’ll only stay a minute, and I can’t let you get out of bed.” [Illustration: THE DOOR SWUNG OPEN SO QUIETLY AND EASILY THAT SHE NEARLY FELL OVER BACKWARD.--_Page 63._] Molly’s heart was beating very fast as she crossed the hall to the dark room, which Grandma used for storing trunks and boxes. There was no one to see her, for both the servants were in the kitchen, and she and Maud had the upper part of the house quite to themselves. The trunk-room was not locked, and she made her way amid various impediments, to the heavy door, which she had always known communicated with the adjoining house. Old Dr. Winslow had had it made in days gone by, when the house next door had belonged to his only brother, of whom he was very fond. This brother had died before the children came to New York, and although the house still belonged to the Winslow family, it had been rented to a lady, who took boarders, much to the disgust of Grandma and Aunt Kate, who looked upon a boarding-house as a blot on the neighborhood. Molly was telling herself that her little sister must have made a mistake. It did not seem possible that the communicating door could have been left unfastened all these years, without the fact having been discovered. With a trembling hand she turned the knob. The door stuck a little, and she was just about to turn away, convinced that Maud had dreamed the whole thing, when suddenly the door swung open, so quietly and easily, that, in her astonishment, she nearly fell over backward. There, sure enough, was the closet, just as Maud had described it. Molly fairly gasped, and in that one moment everything else was forgotten in the excitement of the wonderful discovery she had made. She did not shrink back, as Maud had done, but pushing her way through brooms and brushes, and stumbling over various articles on the floor, reached another door, which she opened, and the next moment she had stepped out into a hall, which was exactly like the hall of their own top floor. It was very quiet, and there was no one to be seen. Molly closed the closet door softly, and stood looking about her. There were four rooms on the floor, and all the doors were closed. The singing lady’s room was in the front, she knew, and after one moment’s hesitation, she stepped boldly forward, and knocked.