Papillon (Natsuya Yikura), an intelligence agent of the National Intelligence Agency, infiltrates a research facility involved in illegal drug development, determined not to allow betrayal among her comrades. After her partner goes missing following his own infiltration, all contact suddenly ceases. To uncover the truth, Papillon infiltrates the facility by gaining the trust of the lab director, but nothing goes according to plan. One after another, ruthless measures are deployed to protect the facility's secrets. Amid intense, high-stakes tension, Papillon fights desperately to save her comrade.