One would have thought that Prudence carried the responsibility for the entire public-school system of the United States upon her shoulders that night, so anxious were her eyes, so grave her face.  Supper over, she quietly suggested to Fairy that she would appreciate the absence of herself and Connie for a time.  And Fairy instantly realized that the twins must be dealt with seriously for something.  So she went in search of Connie, and the two set out for a long walk.  Then Prudence went to the kitchen where the twins were washing the dishes, and as usual, laughing immoderately over something.

Prudence sat down and leaned her elbows on the table, her chin in her palms.  “I met Miss Allen to-day,” she said, closely observing the faces of the twins.  A significant glance flashed between them, and they stiffened instantly.

“She’s very pretty and sweet, isn’t she?” continued Prudence.

“Yes, very,” agreed Lark without any enthusiasm.

“Such pretty hair,” added Carol dispassionately.

“She must be very popular with the scholars,” suggested Prudence.

“Yes, most of them are fond of her,” assented Lark.

“She has rather winsome manners, I think,” said Carol.

“Which of your professors do you like best?” queried Prudence.

“Duck,” they answered unanimously, and with brightening faces.

“Why?”

“Because he is a duck,” said Carol, and they all laughed.  But Prudence returned to the charge without delay.

“Do you like Miss Allen?” She was going through these questions with such solemnity that the twins’ suspicions had been aroused right at the start.  What had Miss Allen told their sister?  Again that significant flash from twin to twin.

“She certainly has very likeable ways,” said Lark shrewdly.

“But do you like her?” insisted Prudence.

“I would like her very much under ordinary circumstances,” admitted Carol.

“What is unusual about the circumstances?” Prudence wanted to know.

“Look here, Prudence, what did Miss Allen tell you?  Was she complaining about us?  We’ve been very nice and orderly, I’m sure.”  Lark was aggrieved.

“She wasn’t complaining.  She likes you both.  But she says you do not like her.  I want to know why.”

“Well, if you must know, Miss Allen is a heretic,” snapped Lark.

Then Prudence leaned back in her chair and gazed at the flushed faces of the twins for two full minutes.

“A—­a—­a what?” she ejaculated, when power of speech returned to her.

“Heretic,” said Carol with some relish.  “A heretic!  You know what heresy is, don’t you?  We’ll tell you all about it if you like, now you’ve got things started.”

“We didn’t tell you before because we thought you and father would feel badly about sending us to school to a heretic.  But don’t you worry,—­Miss Allen hasn’t influenced us any.”