In the time of the Great Depression, Lothar De La Rey and his son Manfred own and operate a fleet of fishing trawlers and a cannery. Centaine de Thiry, Manfred's mother and one of Lothar's creditors, seizes his assets in an attempt to recoup her original investment, believing that Lothar will be unable to pay her back in the current financial climate. During their confrontation, Manfred gets into a fight with Centaine's other son and his half-brother, Shasa Courtney, nearly killing him. Now destitute and bitter, Lothar and his friend Swart Hendrick make plans to rob Centaine's diamond mine.
