Wembo makes a late-night trip through the jungle; monkeys play a trick on Mario and Mario returns the favor; Ronnie is afraid of the principal; Eric is not invited to go along on the boat ride and plans revenge; Fred cannot do fractions; Eva Mae's five lively little brothers get her into trouble; Linda Lou wants to do something for Jesus. Happy Hearts continues the tradition of well-written, character-building stories for children. Second of two readers for second grade.