Back home on their parents’ farm outside Bulawayo in Zimbabwe, the Wallace boys team up with Muyunda Munalula, of the Lozi tribe in Zambia. For nearly as long as he can remember, Muyunda has worn a pendant round his neck. When it gets tampered with, Muyunda relates how it came into his possession.His great-grandfather was dying and had told him how as a little boy he had joined the retinue of Lobengula, the last of the Matabele kings, who was reputed to have amassed a fortune in diamonds and gold.After being defeated by the forces of Cecil John Rhodes, the founder of the country that bore his name - Rhodesia (now Zimbabwe), Lobengula is forced to flee his capital of Gu-bulawayo to the north where he dies. His faithful followers, including Muyunda’s great-grandfather, continue to the banks of the Zambezi River where, in a cave in the Batoka Gorges, they hide the treasure.The Wallace Boys and Muyunda set off to find this treasure on horseback, making their starting point the magnificent Victoria Falls, visited and named by David Livingstone in 1855. The boys visit Scottie, a family friend, who proudly shows them the fantastic sights in his Fox Moth biplane. Muyunda for the first time encounters the Wallace Boys’ nemesis, the unholy pair of Isaacs and Lambert. Captured and tortured to reveal what he knows about Lobengulas treasure, Muyunda is left for dead when he falls over the gorge beside the Devil’s Cataract.Eventually, the boys reach the long-lost cave tucked behind a small waterfall that tumbles into the Batoka Gorge many kilometres from the Victoria Falls. Their attempt to find the treasure is nearly thwarted by Isaacs but for the arrival of Scottie in his vintage Fox Moth.