Arthur Bishop is an elite assassin with a strict code and unique talent for cleanly eliminating targets. When his mentor and friend Harry is killed, Bishop is compelled to avenge his death. He takes on Harry's son, Steve, as an apprentice, despite Steve's impulsive and emotional nature. Bishop teaches Steve the art of assassination, and together they embark on a mission to hunt down the murderers.

As they delve into the world of assassination, Steve learns to refine his instinctive aggression into calculated precision under Bishop's guidance. They navigate through a series of hits, which serve as a testing ground for Steve's commitment to the craft and his readiness to discover the complex realities of their profession. The trust between them grows, but the nature of their business makes every step fraught with suspicion and treachery.