St. Madern's was one of the best of modern girls' schools set in wonderful surroundings. There was a popular staff, a competent Head, and an exceedingly good Assistant. But there was a mystery. Without any warning a large number of the girls became listless, a number of them had been removed to other schools at the end of the previous term, and notice had been handed in in respect of others. It was a difficult position, and at the opening of the story no one could find the solution. It was due to the loyalty of a new-comer that the trouble was ultimately traced to its source.