Clayton "Clay" Zachery was a SPARTAN-IV who served aboard the UNSC Infinity as Fireteam Valiant's mission handler. Clayton served as an ODST during the Human-Covenant War, serving during many of the major battles of the final days of the war, including the Fall of Reach and the Battle of Earth. After the war, Clayton was among the first recruited SPARTAN-IVs, and passed the selection, training, and augmentation processes with flying colors. Unfortunately, during one of his first deployments as a SPARTAN-IV, Clayton was caught in the blast of an Insurrectionist IED, costing him both of his legs.