for those of you that dont know who the 2 betrayals are they are the Master chief and 343 guilty spark, because they worked together to get the index and to activate halo. the Master Chief thought that activating halo would stop the flood. but when cortana interrorgated 343 he revealed that halo only depletes the food source of the flood(which is any living organism) meaning that halo destroys all life in the universe. After 343 reveals what Halo really is Master chief is back on cortana's side. Who ever didn't know that is a retard...