"Bang, you're Dead!"
Description - Final words written by professional hit man Arthur Bishop (Charles Bronson) to a younger wannabe assassin Steve McKenna (Jan-Michael Vincent) in the motion picture The Mechanic (1972).
Arthur Bishop is what they call a Mechanic" (aka, a hit man). He carries out assignments for a group called "The Organization" of which his father used to be the head, until a contract was taken out on him. It was Arthur who received the order and he dutifully killed his father.
After his father's death, he was mentored by Harry McKenna (Keenan Wynn) who took him under his wing and became a close friend. But when Harry was no longer any use to the Organization, he was killed.
After Steve's father died, he asks if Arthur would let him in on the action and teach him to be a hitman. Arthur agrees, but in doing so he angers the Organization who frowned on Arthur not first requesting "permission" to take Steve on as an associate. For breaking the rules, Arthur was targeted for elimination, and this time it was Steve who received the contract to take Arthur out by poisoning his wine.
"Brucine! You'll be dead in a few minutes. Listen, you'll really appreciate this. This stuff is absolutely clear when it's in solution. I just coated the inside of the glass with it and let it dry. When the wine hit it it went right back into solution. No trace. Looks just like a heart attack...You said every man has his jelly spot. Yours was you just couldn't cut it alone...They told you who to hit. Kept the whole idea from being what we talked about. You needed a license, their license. I'm gonna pick my own mark, hit when I want. Just like you said, standing outside. See Naples and die." - Steve
However, when Arthur’s protégé returns to the States to claim his spoils, including Bishop's home and possessions, he sits inside Bishop’s Mustang sports car and finds a note:
“Steve, if you read this it means I didn’t make it back. It also means you’ve broken a filament to a thirteen-second-delay trigger. End of game. Bang, you’re dead.” [The car explodes].
Arthur had found the order for Steve to kill him and arranged a little explosion, if he did not return alive from Naples where the two had been send on assignment which was actually an ambush meant to kill Arthur. It failed. That is, until Steve stepped in.
Earlier in the film, Arthur justified his career as a hit man by saying, “Murder is only killing without a license and everybody kills...the army...the police...”
Note: Jason Straham starred as assassin Arthur Bishop in the remake of The Mechanic (2011), when he sets out to find those who killed his mentor and best friend, Harry (Donald SUtherland). Ben Foster costarred as the Steve, the son of the dead man, whom Arthur (a reclusive loner) agrees to teach the killing the trade, so Steve, too, can avenge the death of his father. But in the end, Arthur is betrayed by Steve, whom Arthur then kills.
See also - “So Long, Sport!"