Dark Sector

This is story mode, complete the third chapter.

The final piece is a little tricky. After the big fight, you'll come across a fence with a gate. Directly across from the gate on the left side is a red light switch.

Stand a little ways back from the gate, shoot your glaive over the fence. Use aftertouch to guide the glaive into the switch.

This will open the gate, continue on. Level complete.

You'll gain the Power Throw and Aftertouch abilities in this chapter, thus allowing you to start working towards the Hardball, Finesse, and Aftertouch abilities as you play. You'll also encounter the shield guards in this chapter, who can do quite a bit of damage if they close enough to melee. Just use a power throw on their shields and shoot them with your pistol to kill them, and keep a safe distance.

(The video belongs to BonersGames)
(FYI i used http://www.xbox360achievements.org/game/dark-sector/guide/
credit belongs to wickeddark)