At last Nancy rose and smiling mysteriously, said:
"Excuse me, ladies. While your company is highly exciting, I must leave you to write letters."
"I can't imagine to whom," exclaimed Billie.
"I mailed four for you yesterday to your mother and father and 'Merry' and Percy St. Clair."
Billie knew Nancy's affairs quite as well as she knew her own; two sisters could hardly have been more intimately associated.
"Guess again, Miss Inquisitive," said Nancy. "And guess fifty times more if you like. You'll never guess the right person and I shan't tell you for punishment. So there!"
For some reason—of course it was the weather—Billie felt teased and hurt. Not for anything would she have kept Nancy in ignorance of any of her correspondence.
"I didn't mean to be inquisitive." she called, half apologetically. "I was merely surprised at your being so mysterious."
"When you get to be as old as I am," said Nancy in a lofty tone, "you'll know better than to tell all you know."
"I'll never get to be as old as you are, Miss Nancy-Bell," retorted Billie. "It's a physical impossibility, since you are two months older than I am."