— Swift, after Mason talks to his hallucination of Reznov, which Swift does not know about.
Swift was a character in Call of Duty: Black Ops as part of the Studies and Observation Group. Swift appeared in the mission "Victor Charlie" where he progressed through the Viet Cong tunnel network with Mason. After entering the tunnels, Mason encountered his hallucination of Viktor Reznov again, confusing Swift as it would appear to him that Mason was talking to himself. Unfortunately, this momentary distraction allowed a Viet Cong soldier to ambush Swift from around a corner and fatally stab him in the heart.
If the player tries to sprint at Swift before he dies, he says "Back the fuck up", done to prevent the player from getting past Swift and saving him.
On the Wii version, however, the player can easily get past Swift. They will see that the Vietcong is not standing there. However, he has spawned, as the player can see his hand sticking out of the cave wall. When the trigger is activated, the Vietcong will dash through the cave wall and stab Swift.