Comprised in late 2558, Fireteam Guardian was formed to hunt down Promethean forces and Covenant Remnant forces. The team was comprised of four Spartan-IVs from all different branches of the military and science divisions. The team would run special operations, normally in a possible Forerunner decide sites and planets. The team is led by Captain Henry Michelson of the Raven's Nest and field lead by Spartan Commander David Greyson.