Gray Team

Gray Team is the designation for a mysterious team of SPARTAN-IIs that are said to be "on battlefields too distant to be easily recalled" when the SPARTANS received the new MJOLNIR Mark V armor. The team was later identified to have been "on a mission far outside the confines of UNSC space, now missing for over a year".

Nothing is known about the three Spartans or what their mission was. It is possible that their story will be told in upcoming Halo novels. Eric Nylund has commented that he has interest in telling their story, but it is unclear if he will be writing any of the future Halo novels on contract with Tor publishings.