Detective Ratso investigates the murder of secretive London businessman, Seb Marston, executed at home by a professional assassin. The victim's wife is the hard-driving CEO of an international pharmaceutical company. She may have a motive but as Ratso untangles the victim's complex lifestyle, other suspects emerge from the USA through Scotland to Poland.

Is Hubert Portilla really a Mexican diplomat based in the United Nations in New York? Or is he a conman ready to trap the unwary in multi-million global scams? Was Marston into espionage in diplomatic circles? With pointers to American involvement and death threats from a Polish gangster, Jed Forster, Marston's millionaire business partner, lives in daily fear for his life. But from whom?

Is there a link between the conman and the assassin? What, if anything, is the conman planning? Despite intense efforts by the FBI, the French police and Ratso's London team, both assassin and conman remain an elusive and dangerous double threat. Ratso must track them down before Forster is murdered and more victims are conned or murdered.

In Deadly Shadows ? fiction follows truth. The plot was inspired by a true and murderous story as explained in the Afterword.