Blind run - Patricia Lewin

Sydney has worked hard to get her life back together after the death of her young son and the subsequent break-down of her marriage. She's not ready for her ex-husband to walk back into her life. But now Ethan Decker needs Sydney's help.
Once an agent for one of the most secretive departments of the US government, Ethan's job had been to track ruthless international mercenaries and fugitives. After the loss of his son, Ethan had turned his back on his wife, his mission and his former life, to live in self-imposed exile in the desert. But Ethan's past catches up with him when he is visited by a former colleague who entrusts Ethan with the safety of two young children before being killed. The Spanish coin he finds under her tongue is a mark Ethan hoped never to see again: the mark of the assassin Ramirez. And if Ramirez is back then Sydney herself is in danger.
The race is on: for Ethan and Sydney to stay one step ahead of Ramirez, whilst protecting their two young charges and attempting to unlock the mystery of why they also appear to be on Ramirez's hit list.