Halo 5 plot ideas. ever herd of mendicant bias? he is a forerunner AI that was given the tasked with the study of the primordium(a flood gravemind) to find ways to stop it. after 43 years of talking with it he was persuaded to assist the flood with the destruction of the forerunners. the eventually stopped him, disassembled him and buried part of his systems on the ark. you may think he has no relevance to anyone anymore but in halo 3 you can find terminals to interact with that display massages from him to the master chief saying that he is repentant and wants to assist the chief in his journey. so I would not be surprised if the flood return in "halo 5" and I would love to see that happen. as for master chief in the teaser trailer I think he is trying to find this AI to get help. can't wait till e3 2014 to see what is true and what is false. i like campaign better than multiplayer so i hope they make it long and AWE INSPIRING!