Carol Davis is mourning the death of her fiancee in a car crash and is visited in bizarre circumstances by his brother Greg Farrell who convinces her that the death was not an accident but murder. It appears that in his work as an investigative journalist he was getting close to uncovering a conspiracy in which an eminent M.P. Sir Henry Marshall was heavily involved. Greg Farrell knows more than he is willing to share with Davis, not least that a pair of internationally renowned killers, The Retaliators, have been hired to carry out a double assignation on high ranking officials. Although sceptical and curious as to why he seems to know so much about Mike's work and is always evasive about his occupation, since he is obviously well acquainted with the life they have to enter, she agrees to help in finding out the truth and tracking down the killers. Experiencing new feelings when close to Farrell, she finds life exciting even though it is sordid and deadly and on more than one occasion is forced to kill to stay alive. In their quest they learn that Marshall is one of a quartet of men, led by Simon Parker a rich and powerful entrepreneur, who had hired the assassins but had planned to renege on the deal and have them killed once their side of the contract had been completed. The couple however learn of the double cross against them and in anger systematically kill all those who had become involved, which includes both Farrell and Davis as they are caught in the cross-fire. The clues lead to a farmhouse in Normandy where Farrell faces the killers and thinks his chase has ended when both are presumed to have died but future events prove otherwise and as Davis fights for her life after being shot he has to track them down again and matters are finally settled on an archaeological site in Sicily."