ok i stopped at the part umm the covanant. its when we have to shut down 3 towers. you, arbiter, and johnson are split into teams. you and arbiter succeed but johnson is cought up with truth. yeah anyways i saved at that point like deep in the chapter. then my brother goes back in the story when the flood come in right after truth activates this huge portal to find a skull there. he couldnt find it so he saved and quit. when he went back to were i left off which is the covanent we had to restart all the way to the beginning. what happened and how can i get back to were i was??? oh and this whole thing is on the level Heroic.