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. Psych nurse Gillian Coates wants to find her sister's killer. She does not believe that Belle Coates, an ICU nurse, took her own life, even though every bit of evidence indicates that she did, every bit save one. Together, Nick and Gillian determine that one-by-one, each of those in the operating room for a fatally botched case is dying. Their discoveries pit them against genius Franz Koller, the highly-paid master of the "non-kill", the art of murder that does not look like murder. As Doctor and nurse move closer to finding the terrifying secret behind these killings, Koller has been given a new directive: his mission will not be complete until Gillian Coates and Garrity, the last surgeon, are dead.