Gravemind is a Halo 2 campaign level. The level takes place within High Charity, after the Gravemind teleports John-117 there. The Prophet of Truth has the Index, and you must get to him before he leaves for the control room of Delta Halo. As you travel through High Charity, you will experience the beginning of the Covenant Civil War. Strangely enough, apart from the opening cutscene, there is no contact with the Gravemind or the Flood. Also, the word "Gravemind" is not mentioned until two levels later in High Charity. This is also the level where the Energy Sword appears most often, and is one of only four missions where there are no Human weapons. This is the first level in which you can use the Brute Shot and the Brute Plasma Rifle. You also fight Brutes for the first time here.