Six White Horses (Electronic book text)

Palmer, a Marine in California, has been railroaded to jail by his crooked sergeant. He manages to escape and, reluctantly leaving his pregnant girlfriend, flees to Mexico.

Now, seven years later, ex-Sgt. Wilde is a rich drug dealer, selling the deadly synthetic heroin, fetanyl. The murder of the "mule" who brings the drug over the border leaves Wilde badly in need of a new courier. Fate delivers one in an encounter with Palmer in the small Mexican town where Wilde's supplier is. Wilde holds all the cards here, but Palmer is desperate. Desperation, however, doesn't make Palmer as easy to control as Wilde thinks....

The conflict climaxes to a battle over the lives of Palmer's woman and son in a scene more breathtaking than any shootout.