Flint Sparks and his human Jon, both former mercenaries, have settled down in quiet retirement from an industry where the job is supposed to be forever. But, unlike anyone before, they found a way out. However, this new life, filled with peace and joy, is not to be. In the dead of night, some of their former "colleagues," who disagree with their decision to retire, break into their home and murder Jon, leaving Flint alive in the bloody aftermath. They killed his human. He wants revenge.