Ghost fragment. I have seen some people ask what the "Nine" is. [quote]The Nine are survivors of the cis-Jovian colonies who made a compact with an alien force to ensure their own survival. The Nine are deep-orbit warminds who weathered the Collapse in hardened stealth platforms. The Nine are ancient leviathan intelligences from the seas of Europa or the hydrocarbon pits of Titan. The Nine arrived in a mysterious transmission from the direction of the Corona-Borealis supercluster. The Nine are the firstborn Awoken and their minds now race down the field lines of the Jupiter-Io flux tube. The Nine are Ghosts who pierced the Deep Black without a ship and meditated on the hissing silence of the heliopause. The Nine are the aspects of the Darkness, broken by the Traveler's rebuke, working to destroy us from within. The Nine is a viral language of pure meaning. The Nine are the shadows left by the annihilation of a transcendent shape, burned into the weft of what is. [/quote]

wouldn't surprise me, bungie loves to reference their older games in their new ones all the time.