In 1912, Dan Rockland [George Segal] arrives in West Africa, posing as a geologist, but he is actually employed by Kramer [Harry Andrews], whose diamond business thrives on bold risks and secrecy. The laborers under Kramer uncover a massive uncut gem, a prize that promises to shape futures, and the jewel is soon christened and pursued as The Southern Star. Rockland, accompanied by his African confidant Matakit [Johnny Sekka], travels by train to carry the gleaming fortune back to Kramer, intent on delivering it despite the perilous path ahead.
Their journey takes a dark turn when Captain Karl Ludwig [Ian Hendry], consumed by jealousy over Rockland’s engagement to Erica Kramer [Ursula Andress], sabotages the train, blowing it apart and severing the route to the gem. The discovery party turns into a crisis as chaos erupts during a lavish celebration hosted by Kramer to honor the unearthing of the gem, and the blackout plunges the gathering into confusion. In the aftermath, the diamond vanishes from sight, and Matakit is wrongly suspected, forcing him to flee on a pet ostrich amidst the growing suspicion.
Rockland, believed by many to be an accomplice, escapes from prison with the unexpected help of Erica, and the pair press on to track Matakit down. Karl and his henchmen trail them, driven by the same motive—to seize the diamond for themselves. The alarm spreads quickly to Major Plankett [Orson Welles], Kramer’s former security chief who was ousted when Karl took over, and who swears revenge on those who wronged him. Plankett captures Matakit and uses him as a pawn to draw Karl into a trap, turning the web of deception into a deadly confrontation.
Yet the move of chess continues as Karl manages to flip Matakit’s position to lure Rockland into a deadly ambush. What follows is a tense showdown where courage, cunning, and quick action determine the fate of the gem. Rockland performs a daring rescue of Matakit just as the tide turns, and Karl falls in a climactic shootout. With Karl defeated, Rockland reclaimS the gem for Kramer, restoring the balance of power and leaving the future of the Southern Star in the hands of those who survive the gamble. The tale closes on a note of wary relief, where loyalty is tested, alliances shift, and a fragile treasure—The Southern Star—finds its rightful owner, even as the shadows of betrayal linger.
