Mata follows the story of a French secret agent who is wounded during a covert mission in Niger. During this operation, her colleague Antoine is captured, leaving her both physically and emotionally scarred. Upon her return to France, Mata volunteers for a counter-espionage mission in the Alps. She suspects that this new assignment is somehow linked to her traumatic experience in Africa. As she delves deeper into the mission, Mata becomes increasingly convinced that her superiors are concealing critical information from her. Determined to uncover the truth, she operates outside official channels, risking her career and her personal safety.