The Black shrike

the long version

Rocket fuel expert (and intelligence agent) John Bentall is sent on a hazardous mission: find out why many leading rocket scientists have disappeared after answering newspaper ads for mysterious positions in Australia. He (along with the beautiful agent posing as his wife) are to be dangled as bait, and it isn't long before they are snatched up and led into a situation where appearances are deceiving and misplaced trust can be deadly. - alistairmaclean.com.