From Apocalypse Now
Your mission is to proceed up the Nung River in a Navy patrol boat. Pick up Colonel Kurtz's path at Nu Mung Ba, follow it and learn what you can along the way. When you find the Colonel, infiltrate his team by whatever means available and terminate the Colonel's command.
Terminate the Colonel?
He's out there operating without any decent restraint, totally beyond the pale of any acceptable human conduct. And he is still in the field commanding troops.
Terminate with extreme prejudice.
You understand, Captain, that this mission does not exist, nor will it ever exist...