Effect: Very hard to remove an enemy's armor. You will hate the Brutes.
Instructions:Race through the mission (don't worry about the Flood) until you reach a large flat platform and hear Cortana talk about "games" and how she "likes playing too." Search near the back rock wall for a little metal nub with an arrow pointing up. Begin your ascent there, jumping from ledge to ledge until you reach the flesh-colored pipe. Walk across to the upper platform, where the skull resides.