Arthur Bishop is a 'mechanic' - an elite assassin with a strict code and unique talent for cleanly eliminating targets. It's a job that requires professional perfection and total detachment, and Bishop is the best in the business. But when his mentor and close friend Harry is murdered, Bishop is anything but detached. His next assignment is self-imposed - he wants those responsible dead. His mission grows complicated when Harry's son Steve approaches him with the same vengeful goal and a determination to learn Bishop's trade.