Dr Adam Knox returns from the war in Afghanistan a little rougher, a little wiser, and a lot more inclined to kick it to the ones at the top. The ones in charge.
He sets up a clinic in Los Angeles's most notorious district, tending to the vagrant, the vulnerable and the victims of skid row. One night they're beseeched by a Romanian woman who comes in with her son. Her bruises give away a story she's too scared to tell; escaping from traffickers and forced prostitution to try to get her son back. He was kidnapped by his father - who happens to be heir to one of the most influential dynasties on the West Coast.
That same night, Knox is called upon for his private health service - cutting out a bullet from a businessman who was cutting himself a shady deal. Impressed by his ability to keep a secret, the impatient patient offers Knox a big tip for some extra work: helping him get revenge on the gangsters who shot him. Knox - and his clinic - need the cash.
Playing one team against another, Knox must keep his wits scalpel-sharp. If his diagnosis is on the money, he might be able to trick the gangsters, free the Romanian mother and put the ones at the top in their place for once.