"Probably it was Jack Goodrich from Harvard. He lives in Detroit and he and Marjorie have always been good friends. Now tell me about your vacation."

They began an exchange of experiences but were interrupted every few minutes by girls coming in to welcome them back. Nearly every one ended with, "Did you make your costume for Monday night?" It was late when Jean and Elizabeth found themselves alone without fear of further interruption. "Jean," said Elizabeth, "I want to thank you for what you did for us all at Christmas, and most of all for Brother's gift. He has written you, too, but I must tell you all that it means to me, for I feel as though it were benefiting me as much as him. To think that he can go to college next year! I can hardly believe it now, although I have thought and talked of little else all the vacation. How could you be so generous?"

"Oh, let's not talk about it, Elizabeth. You know I have more spending money than I know how to use, and father helped some because I wrote him all about Dick and his patience and courage and talent. You can finish your course, too, perhaps, and Dick be in college at the same time. So let's not ever say anything more about it."

The costume party was to be held in the dining-room, reading-room, and hall of Merton, and all the afternoon the girls strung Japanese lanterns and brought down furniture from rooms above to make as many cozy corners as space allowed. Supper was to be a little early, and after it was over the tables and chairs were to be moved out and the floors waxed. The electric lights were covered with red paper to dim their brightness, and the piano was moved out into the center of the living-room so that the music could be heard better in all the rooms.

By eight o'clock most of the girls were downstairs, and in their costumes and masks presented an attractive appearance. Half of the girls wore men's costumes of all periods, and there were kings and queens, clowns and French dolls, Quakers and follies, peasant maids from many countries, shepherds and shepherdesses, Topsies, Marguerites and priests, nuns and dancing maids were present, and others too numerous to mention. A local pianist had been hired, and she was the only one in the room not in costume. Even Mrs. Thompson was somewhere in the merry throng.

There was first a grand march to be followed by dancing until ten o'clock, when the unmasking was to take place and light refreshments served. Gradually, little groups of girls thought they recognized each other and surmised the identity of certain others. Jean and Elizabeth and Sallie Lawrence were resting after a strenuous Virginia Reel. "Who is that couple who have danced together all the evening, the tall monk and the demure sister of charity? Probably she thinks it's her duty to confess to him for her worldly dissipation. The sister of charity looks like Marjorie Remington, but who can the monk be? Marjorie doesn't generally remain so faithful to one partner," said Sallie.

"It is Marjorie," said Jean; "I can tell her walk anywhere and I'm sure those are her pumps. She told me she bought them in Detroit this last vacation. I'm sure I can't imagine who her partner is. The tallest girl I know is Mary Stickney. It must be she, but isn't it queer Marjorie should care to dance so often with her? Probably she thinks it's more picturesque to dance with a monk. I remember asking Mary this afternoon if she was going to-night and she said she didn't believe so, but if she did she'd have to get up something very simple at the last moment. That monk's costume is surely the simplest one here."

After several of the girls had asked the charming sister of charity to dance and she had shaken her pretty head and persisted in dancing with the monk, all the others began to wonder a bit and talk among themselves. "Who is the monk?" was on everybody's tongue, and it was pretty generally conceded to be Mary Stickney.

Just before ten the monk and his fair partner slowly left the main room for a lemonade table at the end of the hall. Most of the others were dancing, but Jean, very tired with the excitement of the evening, had slipped alone into a little cozy corner just beyond the lemonade table. She did not intend to watch or to listen, but she could not help herself. When the two dancers were left to themselves, she heard Marjorie Remington say, "Hasn't it been splendid, Jack? Not a soul ever would suspect, for you certainly took every precaution. But I think you'd better go now, for it's almost time to unmask. Take off your robe and mask in the outer hall and you'll find your cap and coat and shoes in my suit-case there in the right-hand corner. You'll not meet any one, for everybody in the house is at the dance and it's too late for outsiders to be coming in. Still, be cautious. Let me know how you get back to Cambridge, and come out as soon as you can. Good night, dear. Don't let anything happen to you." And the black-robed priest disappeared from view and the demure little sister of charity sat down a few minutes in the dimly-lighted hall to rest.