The Fountain by Kathryn Le Veque

After the death of her husband, Katharine “Kiki” Delohr Conrad moves back to her home town of Pasadena, California with the intent of starting a new life.
With her trusty French Bulldog, Stanley, by her side, Kiki buys on old fixer-upper and has big dreams of turning the home into a bed and breakfast. Unfortunately, the old home, known as Agua de la Vida, is more work than she anticipated. When a sexy contractor gives her an estimate to restore the place, Kiki is in a quandary – she is attracted to the blond, blue-eyed hunk, but repelled by the money he estimates a restoration of the house will eat up.

What’s a girl to do?
Trace Rocklin is that sexy contractor. Or, at least, that’s what he pretends he is. The truth is that Trace was a CIA assassin, now returning to his home town to try and forget that part of his life by going to work in the family construction business. But trouble follows him, even as he falls for the owner of a derelict old house. Soon, Kiki is in danger and Trace is drawn back into the world of intrigue he’s trying so hard to forget. In order to save Kiki, and himself, he must temporarily return to that job he’s trying to forget – he must become that assassin again.