While scavenging through Urzikstan in Call of Duty: Modern Warfare 3 Zombies, players will want to complete contracts to earn bonus acquisitions, potential schematics, and earn essence to spend in-game to buy perks and Pack-a-Punch upgrades. One contract players can tackle is the Aether Extractors contract, which will require players to take out three Terminus squads and disable the nearby extractors in the time limit, all while surviving the pursuing horde.