"Is your sister here this evening?" asked one of the boys, addressing Dick.
"No," said Dick, soberly; "she couldn't come."
"I'm sorry for that. She promised to dance with me the first Lancers."
"Wouldn't I do as well?" asked Dick.
"I don't think you would," said the other, laughing. "But I'll tell you what,—you shall dance with my sister."
"I will, with pleasure," said Dick, "if you'll introduce me."
"Why, I thought you knew her," said the other, in surprise.
"Perhaps I did," said Dick; "but I exchanged myself off for another boy just before I came, and that makes a difference, you know. I shouldn't have known you, if you hadn't spoken to me."
"Do you know me now?" asked the other boy, beginning to understand that he had made a mistake.
"You live on Twenty-First Street,—don't you?"