When she catches sight of the dreaded, fever-inducing red frog, eleven-year-old Menna must decide if she will inform the village. Everyone believes the frogs are extinct, and Menna has her doubts about their responsibility for the plague. Her new friend, Florin, the outcast Druid convinces her they are not the cause but actually the cure. Unfortunately, her trust in him is tested when she herself catches the deadly fever. Will Florin be able to convince the village in time to save her life?