Sparks shower down upon Kay Tracey as she watches firemen battle a blaze in Brantwood's library. This distraction, however, does not prevent the teen-age detective from spotting two sinister-looking figures intent on stealing valuable art objects from the burning building. Kay hops into their truck as they drive off. From that moment on she becomes entangled in the weird mystery of the Sacred Feather.

Unlike many others in Brantwood, Kay cannot believe the signs which point to elusive Abou Menzel as the firebug menacing her home town. Together with the Worth twins, peppy Betty and dreamy Wilma, Kay sets about using her skills as a detective in an effort to solve this baffling case.

Surprises -- and danger -- are Kay's lot as she digs deeper into the mystery. Among other obstacles, she has to contend with her classmate Ethel Eaton, who is jealous of Kay's popularity at Carmont High School. Ethel tries underhanded tricks in an attempt to throw her rival off the trail, but Kay has many friends to help her. Kay has many thrills as she hunts the leader of a strange cult that worships fire.