The title says it all. There's a mix up involving stolen diamonds which Ernest has (naturally) made into a yo-yo and given to his would be girlfriend, Rene. But Rene wants a man of action, and doesn't think that Ernest fits the bill. After the bad guys come looking for the stolen diamonds and kidnap Rene, all of her fantasies come true as Ernest has to go to Africa to rescue her.

In 1879 South Africa, the administrators of the British Cape Colony have designs to eliminate the Zulus as a hindrance to their colonial economy. To that end, the British present King Cetshwayo with an impossible ultimatum to provoke a war they are sure they can win easily with their rifles and artillery against native spears. However, that war proves more difficult than the arrogant British commander, Lord Chelmsford, expects as his overburdened army fruitlessly searches for the elusive enemy. However, in the shadow of a hill called Isandlwana, the overconfident British army learns to its sorrow just how badly they have underestimated the tactical skill and might of the Zulu nation.