Jeffery, Janet and Catherine spend their summer school holidays swimming and riding horses in the foothills of the Drakensberg mountains of South Africa. But then they have to deal with bullying teenagers who are into witchcraft, poachers, and the strange guardian of a cave of Bushman paintings. And just when it seems that things couldn't possibly get worse, the children stumble across a secret government project that the police think they know far too much about.