Birkhoff is the geek, the nerd, the computer guy, the eyes and ears of Division. His prior crime was that he accessed and defaced government web sites (CIA, FBI, etc.); he was best known in the criminal underworld as Shadow Walker, an expression you’ll hear him use every chance he gets. While Percy is the mastermind of the operations at Division, Birkhoff is the master brain that facilitates those operations; Birkhoff provides easy access to anything and everything that’s connected, government and corporate alike. He trained new recruits to become familiar with some aspects of his job. While the prospect of living a normal life after Division – some are killed during a mission, others are cancelled (terminated) by Percy – is mere fiction, Birkhoff was siphoning money into a secret account in the hope that if he ever escapes Division, he would have enough money to retire anywhere he wants. His wishes were about to come true when Birkhoff joined Nikita’s crusade, at least the thought that someday his wishes may come true was closer than when he was at Division. But Birkhoff will soon find out that there is no normal life after Division, no matter how much money he has accumulated.