SPARTAN-071, also known as Elena-071, Elena Wagner and Codename: ARCHER was a SPARTAN-II Commando of Project SIGMA. One of twenty candidates not picked for the mainline SPARTAN-II Program, she was abducted at the age of six and trained at a top-secret facility on Earth for eight years. Showing her leadership qualities and incredible skill at an early age, she was marked as a team leader early on and was eventually picked to command Sigma-Beta Team, who would act as a strike force acting directly under ONI's orders. As they were marked above the rest of their counterparts, her team were made into commissioned officers directly after training to grant them a greater deal of authority in the field.
Following their augmentation procedures, Elena and her two teammates were separated from their comrades, who were told that they had died, and would spend years hunting down Insurrectionist groups across the colonies as the Human-Covenant War began. As the war escalated, Elena would begin leading her team on high-risk missions behind enemy lines to disrupt Covenant supply chains and keep their forces in disarray. After seeing success in numerous operations over the years, Elena lost both her teammates during the Battle of Schönheit in 2545 and began to work on solo operations for the Office of Naval Intelligence, accumulating some political power within the organisation in addition to her prowess in the field. After finally reuniting with her fellow SIGMA Spartans following the Fall of Reach in 2552, she would play an important role in protecting high-ranking military personnel during the Battle of Earth.
In the aftermath of the Human-Covenant War, Elena's field duties diminished somewhat as the SPARTAN-II eventually found her place as one of several liaisons between ONI and the newly-formed Spartan Operations, overseeing the SPARTAN-III Shrike Team for the duration of its existence and helping to manage a number of classified deployments over the next few years. While she possessed no fixed station in the turbulent post-war years as she moved from one mission to another, Elena often oversaw missions undertaken by her closest friends in Sigma Team as their unofficial handler, occasionally joining them on operations.