Mission: The Ark
Effect: Killed enemies drop half the amount of ammo they usually do.
Instructions:Your Warthog will eventually reach a fork in the road, where you can continue forward or turn right. Turn right. You'll find a group of Ghosts and, on the left, a large stone structure. Climb the rocks on the right, jump over to the structure and head for the last support beam. Resting on its most precarious tip is the skull. Grenade jump, stand on a friend or bring one of the Ghosts up for the needed height.