According to the cover blurb of my 1971 Pan paperback edition Victor Canning is one of the top six thriller writers in the world. This one is predicated on the slightly flimsy premise of a Mr Evil blackmailing various politicians, actresses and academics, extorting an annual fee for not disclosing sordid details of their pasts. It transpires that these misdemeanours are rather trivial by today's standards and would hardly merit a social media storm, let alone halt their successful careers, but, nevertheless, it enrages a gung-ho botanist with the decidedly unheroic name of George Constantine to try and put a stop to the little game. George's main tactic is to go blundering into danger at every possible opportunity with no back-up apart from the daughter of one the blackmail victims whom he disarms early on ("a woman with a gun, backed into a corner, is an unreliable quantity"). Having been caught and beaten up several times by the former French Resistance baddies, who make the basic error of explaining to George exactly what they are going to do with him before allowing him to escape, George decides that valour is the better part of discretion and ends up as a prisoner in a health spa for hotel waiters in the Alps (where the baddies make the the basic error... etc etc). All told, it's no Ian Fleming, Alistair Maclean, Desmond Bagley or Hammond Innes (although probably is in the top six) but the writing is concise and the action moves along at breathtaking speed with a satisfying amount of sexual tension. It would have made a great ITV serial in its day.
A suave master-criminal blackmailer, a manly adventurer on his trail, a sexy blonde sidekick, picturesque European locales, and hair-raising escapes from certain death: a good time will be had by all.