The Black Shrike (The Dark Crusader)

Eight job advertisements. Eight jobs. Eight specialists in modern technology required. Eight scientists to fill them. Applicants to be married, with no children, and prepared to travel. Highly persuasive salaries. One criminal mastermind. Eight positions filled. Eight scientists - and their wives - disappear. Completely. One secret agent to stop him.Advertisment no.9. Sydney, Australia. Fuel specialist required. Looks like a job for John Bentall-