W.A.S.P. in Stage 6
After the first level transition after reaching the Citadel, open the door and look to the left. On the ground is a trapdoor. Blast it. Be careful: on your right will be three soldiers; one high and two at street-level.
Drop down into the trap door. Activate nightvision. Head down the tunnel. There's a wall to blast. Look at the floor beyond the wall. Destroy the planks. Drop into the hole, squat and move down the tunnel. Pass through the next 'S' tunnel. When you enter the steam chamber, you'll hear soldiers talking. On the platform above will be three soldiers. Kill them with a grenade, or two. Climb up the ladder. As you approach the two W.A.S.P.s on the back wall, you'll get a Bonus Objective award.
Added by: Ichigo Kurosaki Sep 13th 2009, ID#32313