Michael Palmer’s latest novel pits a flawed doctor against a ruthless psychopath, who has made murder his art form. Dr. Nick Garrity, a vet suffering from PTSD—post traumatic stress disorder—spends his days and nights dispensing medical treatment from a mobile clinic to the homeless and disenfranchised in D.C. and Baltimore. In addition, he is constantly on the lookout for his war buddy Umberto Vasquez, who was plucked from the streets by the military four years ago for a secret mission and has not been seen since.