Whitney Cameron is in a quandary: he's attracted to his beautiful sister-in-law, Lynn, but also harbors serious suspicions about her. Her husband, Cameron's brother, died under mysterious circumstances, and now that the death of her stepchild, Polly, has been attributed to poisoning, he suspects that Lynn is after his late brother's estate, and killing everyone in her way.

The Lionians, a tribe of lion worshippers, make a desperate attempt to find a cure for the mysterious disease plaguing their village. Their Chief decides to kidnap Jane and Lola, a half-breed nurse, in order to help repopulate his civilization. Tarzan must rescue them while fending off blowgun attacks from people called the Waddies who are disguised as bushes.

A young boy living at a mountain lodge witnesses a murder, and is then targeted himself by the killer.