The story:
The world is baffled by a number of oil robberies taking place on board giant super tankers in the middle of the ocean. What happens to all the oil? A puzzled Phantom sets out to investigate, starting in the murky wharf area.

Meanwhile, and to the delight of her mother, Diana Palmer has accepted an invitation to spend the evening with the super-rich oil magnate Count Petro. Unknown to both the Phantom and Diana, their paths are soon to converge in the most unlikely way...