Opening with a CGI intro that is very akin to Promotheus, a USNC starship comissioned not for war but for the discovery of new planets crash lands on a world everyone’s favourite Spartan also happens to be on. A massive orb like ship appears and gives chase. First encountering the Covenant only to come across several types of AI creatures. The weaponry dropped by one is identified as Forerunner design.
Often rumoured, Master Chief will be duking out with a returning Forerunner threat in Halo 4.