You are an Elite Special Operation, You are sent by the Elite Captain to find Halo's control center. Jackals and Hunters now betrayed the Covenent and now they are on the Human side. As you continue your mission, You'll meet 2 Grunt squads being led by Elites. Their Covenent dropship was shot down the marines.
Note: You need HMT or HHT to walk on walls at the beginning of the mission.