Operational Detachment-Sigma, also known as DETACHMENT: SIGMA or simply Sigma, was an emergency sub-unit formed as part of the Office of Naval Intelligence's elite Special Activities Division on November 1, 2558, in order to combat the threat of the organization of A.I.s and their Promethean servants, known as the Created. Consisting entirely of Spartan personnel, the group recruited its members from all three surviving generations and units, including the Spartan branch, which had long be ostracized by SAD. As with SAD, de-facto command of ODS lies with the Commander-in-Chief of the Office of Naval Intelligence, Admiral Serin Osman, while field command of the unit was given to Lieutenant, Junior Grade Colin-142, who was given the ability to requisition any operator he deemed necessary. Th