Harry Wingate, a rugged adventurer, is hired by a gem collector to retrieve a priceless opal, known as "The Blue Lightning," from Lester McInally, a super-criminal with an army of killers operating in the Australian outback.

Australian authorities arrest a man believed to be connected to the Sydney criminal underworld and send for Inspector Fang Sing Leng from Hong Kong to question him. After the alleged criminal is assassinated, Inspector Leng and the Sydney police try to hunt down those responsible and hope to solve their case along the way.