The Long Kill — Patrick Ruell

A retired assassin becomes a target in this “feverishly suspenseful . . . tour de force” by the author of the Dalziel and Pascoe mysteries (Publishers Weekly).
 
Best known for his Dalziel and Pascoe novels, which were adapted into a hit BBC series, Reginald Hill proves himself to be a “master of . . . cerebral puzzle mysteries” in his stand-alone thrillers as well -- now available as ebooks (The New York Times).
 
Jaysmith is a hit man highly regarded for his telescopic flair for the “long kill.” Until failing eyesight results in a career-first: Jaysmith misses his target. Perhaps it's time to retire. Where better than the English Lake District? He's fallen for beautiful young widow and single mother Anya Wilson, and has found himself a cozy cottage where he can hang up his M1. Just two problems: Anya's loving father is the man he was hired to kill, and Jaysmith's vicious handlers aren't letting him -- or his intended target -- off the hook. Even if it means taking out Anya and her son with him. For Jaysmith, it's going to be another first: defend, rather than destroy. But this time he's really got to focus.