The Adventures of Peter Wheat #43

Peter Wheat and his companion venture out after winter's snow melts to sail on a lake, but become trapped in a dark cave where they encounter sleeping bats. When the bats awaken, Peter and his friend flee through an underground cavern system inhabited by talking frogs and other creatures who plan to enslave them. With the help of a firefly and a beetle named Beetle, Peter manages to escape the pit and is rescued from danger just in time.