Two young women arrive in London to make it big in show business, and become corrupted by money and fame in the process.

Cass followed the bright lights to London and was quickly disillusioned. She met and married Doctor Langdon, but soon realised she wanted to return to her home by the sea, and to her first love, Colin.

Grisly strangulations in London alert Nayland Smith of Scotland Yard to the possibility that fiendish Fu Manchu may not after all be dead, even though Smith witnessed his execution. A killer spray made from Tibetan berries seems to be involved and clues keep leading back to the Thames.