This is Call Of Duty Modern Warfare 4 Sniper Mission
(One Shot , One Kill)

and in this mission last Objective Say:

(Carry Cpt. Macmillan And Go To Heicopter)

And to play mission correctly You Must Download This Mod Link:

http://www.gamemodding.net/en/gta-san-andreas/gta-sa-cleo-scripts/46379-taskat-trup-drag-corpse-mod.html

And Go To death Cpt. Macmillan then press "E"

Note: This Mod Not Made By Me