After leaving the rainforests of Indonesia, and outwitting the terrible Christian Hayter, Bunty Brownlee takes her grandchildren Bea and Carter, and Carter's newly domesticated Black Dwarf Tyrant, to a safari reserve in Kenya, built to protect the endangered White Titan Tyrants. But soon the children are caught up in a sinister plot involving poaching and diamond-mining. The young heroes require the aid of the Steggi, a nomadic tribe who live in harmony with their prized Stegosaurs...