Set against the backdrop of Soviet, post-war Russia, Birth of an Assassin follows the transformation of Jez Kornfeld from wide-eyed recruit to avenging outlaw. Amidst a murky underworld of flesh-trafficking, prostitution and institutionalized corruption, the elite Jewish soldier is thrown into a world where nothing is what it seems, nobody can be trusted, and everything can be violently torn from him.

Given the order to disperse and arrest a crowd of Jewish demonstrators, Jez breaks up the rally but finds his sisters in their ranks. Rushed for a solution, he sneaks the girls from under the noses of secret police and hides them in downtown Moscow. But he knows they will no longer be safe in Russia and that his own security has been compromised. His plan to cross into the Ukraine to a port on the Black Sea where he can bribe passage from Soviet soil for his sisters seems sound, but he is unaware that his every move is being observed and that he is setting in motion a chain of events that will plunge his life into a headlong battle just to stay alive.

A report on his activities is written, but Jez's commanding officer, Michel Petrichova, has it stored in the Kremlin without further action. A corrupt captain, Otto Mitrokhin, gets hold of the document and uses his civilian accomplices to setup the route to traffic peasant girls into prostitution, having tricked them into thinking they are headed for a better life. One of the girls discovers what is going on, escapes and reports the abductions to the authorities. Michel suspects Otto's involvement and gives him the task of investigating, hoping he will make a mistake and incriminate himself.

Otto sees through the subterfuge, covertly passes the task to Jez, and frames him for trafficking and murder. Realizing he won’t be able to convince anyone of his innocence, Jez escapes. He determines to get away from the collective, but then the person closest to him in life is shot down. When the grief subsides, Jez is overcome by a deadly and unforgiving anger. He’s had the preparation for every aspect of war and now he is about to use it against a host of powerful enemies.