Arthur Bishop (Jason Statham) is The Mechanic – an elite assassin with a unique talent for eliminating targets with deadly skill and total emotional detachment. To be the best in the business Bishop has given everything to realising professional perfection, the last and only attachment in his life is to his mentor and friend Harry (Donald Sutherland). When Harry is murdered Bishop takes on a self-imposed assignment to kill the murderers, using Harry’s own legacy to avenge his death. Things get complicated when Harry’s son Steve (Ben Foster) emerges with the same vengeful goal and a determination to learn Bishop’s trade. Unable to turn his back on Harry’s son, Bishop goes against his vow to always work alone and takes on an apprentice; and when the methodical, detached professional takes on the impulsive, emotional student a deadly partnership is born. But while in pursuit of their ultimate mark, deceptions threaten to surface and those hired to fix problems become the problems themselves.