Margaret-053 (Earth-5875)

Chief Petty Officer Margaret-053 was a SPARTAN-II supersoldier of the UNSC Naval Special Warfare Command. The leader of the covert SPARTAN-II Black Team, under the callsign Black-One, she and her team act at the behest of the Office of Naval Intelligence performing numerous classified and morally questionable operations.

Early life and conscription
Margaret was born on March 12th, 2511, on the Outer colony Bhuj. When she was only six years old, in 2517, she was kidnapped by the Office of Naval Intelligence as a conscripted participant in the SPARTAN-II Program, headed by Dr. Catherine Halsey and Chief Petty Officer Franklin Mendez, on Reach. Like all others, she was trained by Mendez and the synthetic Déjà, and was assigned to be the leader of Black Team - consisting of herself, Otto-031, Victor-101, and Roma-143. During her training days she attempted to escape with her fellow SPARTAN-II Otto-031, for whom she developed a romantic interest. Their affair was discovered by a jealous Victor-101, who revealed it to Chief Mendez and Dr. Halsey, who in turn sent the duo to the brig.

During one of their training sessions, Red Team fought against Black Team, where they attacked Margaret after claiming she did not take the training seriously. During the fist fight, she lost her left eye, leading Black Team to have their payback against their fellow SPARTANs, leading them to remain ten days in solitary. Physically and mentally broken, Margaret and Otto's desire to escape only enhanced, leading the trainers who attempted to recapture them to end with broken ankles, lost toes, fingers, and eyes.

Black Team
Margaret's trangressions led her to be met by Dr. Halsey in her office at the Reach FLEETCOM Military Complex. There, Halsey gave the teenager the choice of returning home and leave the SPARTAN-II Program under the condition she underwent neural paralysis, saying that if she and Otto attempted to escape again they would be shot with neural paralysis darts and awaken back in their home cities without recalling past events. However, she said this drug also reacted horribly on teens and children, and thus their memories could be erased. Halsey then went deeper into the SPARTAN's pysche and asked how would she feel to forget Otto, telling her that she orphanage she lived in did not notice she was missing. This was enough to discourage Maggie from ever escaping again.

Later the same night, Chief Mendez and Halsey reunited Black Team and branded them a specialized squad far from the normal chain of command. After undergoing the SPARTAN-II Enhancement Program in 2525, she was officially nominated the leader of Black Team.