Three years ago, Vesper Rook, Arclight’s first female supreme commander and legendary sniper, was declared dead after a deliberate residential fire broke out while she was investigating an arms theft case. Three years later, having lost her memory and operating under the alias Mara Ellery, she entered the Blackridge Training Center, only to be targeted and suppressed by Captain Breck Danner and Isolde Wren, daughter of an Arclight director, after she reported falsified arms records. Relying on her lingering combat instincts, Mara completed an extreme sniper shot to save female soldier Zadie Navarro and fought her way through the underground Black Halo, gradually uncovering that she was the legendary "Nightglass". Her former husband, counterintelligence analyst Rhys Calder, recognized her, yet only provided her with evidence without demanding that she return to their marriage. As her memories of the fire resurfaced, Mara discovered that Silas Kade, the base’s deputy commander, not only masterminded the arson but also used hypnosis to train her as a tool for political assassinations. Facing the Wren family’s coup attempt, she reclaimed her name, rank and command authority with her own hands, foiled the assassination of the oversight chairman, and managed to rescue and defuse the bomb strapped to her body after being tied up with an explosive vest.
