Der Fluch des schwarzen Rubin (1965)

A valuable piece of jewelry belonging to the family of the Thai Prince Gulab has been stolen from a museum in Bangkok. Immediately after the robbery, the Thai thief is shot by a Western-looking man, who takes the gold chain. The chain is adorned with a black ruby. It has great symbolic value for Gulab, since it proves that he is the rightful ruler of his dynasty. According to legend, anyone who possesses the piece of jewelry unlawfully will meet a violent death. When all the Thai police’s investigations lead nowhere, Prince Gulab asks international private detective Rolf Torring for help. Torring brings along his pal Hans Warren and their Black companion, Pongo. On the drive from the airport into the city, Warren narrowly escapes an acid attack. Clearly, someone knows the Europeans have arrived and wants to sabotage their work from the outset. Accompanied by a tame monkey, the three follow the few clues available. They are joined by Mitra, the beautiful assistant to the museum director, who turns out in the end to be a bona fide Thai princess and heir to the throne. The hunt for the jewelry soon becomes a fight for life and death in Bangkok and the Thai wilderness, complete with unwelcome encounters with tigers, snakes, and trigger-happy killers. Eventually, it emerges that a geologist named Perkins is behind the scheme. Perkins sees the arrangement of the gemstones as the key to uranium deposits that he is determined to claim for himself.