The narrative follows a circle of schoolboy friends, chiefly Fudge Shaw and Perry Hull, as they navigate campus life while preparing their athletic teams. Through tryouts, training, games, and a persistent rivalry with a neighboring school, the boys face setbacks, pranks, and organizational challenges including a change of coach and a threatened railway incident. The action builds through field and baseball contests to a decisive meet where teamwork, perseverance, and sportsmanship determine whether the school earns its coveted purple pennant.