Play the Nijmegen Bridge level at the part where you kill all the people as you get sniped out by the people in the rafters. Enable the "Silver bullet mode" and "Bullet shield" codes and climb the ladder. Kill everyone up there. As you climb down. look at the man laying at the bottom of the ladder. He looks dead but zoom in on his face with the sniper. He blinks, moves his lips, but cannot die.