Miss Felicity Fox is a wonderful teacher. She buys donuts and chocolate cakes with lovely pink icing for all the children in her class. All the children love Miss Fox. All, that is, except naughty Lily Lamb, the naughtiest girl in school. When Miss Fox takes the class on a long and lonely nature walk, Lily is the only one who suspects that Miss Fox's dazzling smile conceals a sinister scheme.