Scripted by Sasori in USA’s Daisuke Goto, Scorpion: Double Venom (サソリ・女囚701号, Sasori: Joshuu 701-go) brings Nami back to Japan but with an all new backstory and motivation for revenge. In the films up to this point, Nami is betrayed by a man she loves and thereafter seeks a revenge that becomes progressively less personal, striking out against entrenched patriarchy and societal misogyny. This time, however, she’s to avenge the death of a girl she couldn’t save, her sister, Yumi, who was kidnapped and murdered as a child.

Like that of Sasori in the USA, this Nami (Chiharu Komatsu) is a highly educated woman, in fact a doctor. Immediately recognising a patient as the man responsible for abducting her sister all those years ago she is left with a dilemma. She confronts him and he laughs at her. As it turns out, the statute of limitations on his crime ran out the day before, so Nami’s plan to turn him in to the police is rendered a no go. As he continues to taunt her and makes suggestive comments about the little girl inexplicably in the next bed sharing a ward with an adult man, Nami ends up stabbing him to death with her scalpel but just before he dies, he tells her that he didn’t kill her sister after all. It was his accomplice, a one-armed man!

Nevertheless, Nami’s revenge will be delayed because she’s quickly carted off to prison for 10 years of hard labour. Unlike those in the other films, this prison is mainly run by women but the warden is a predatory lesbian who extracts sexual favours from the inmates with the vague promise of early parole and claims that this place is like heaven if you play by the rules. After getting sent to solitary for fighting, Nami befriends another woman, Sayuri (Miho Kiuchi), who reminds her of her younger sister, and discovers that she is shortly to be executed at the gallows hidden in the deepest recesses of the prison. Sayuri is apparently not guilty of the crime for which she is serving her sentence but was talked into taking the fall for a sleazy politician who murdered her friend so that her older sister’s medical bills would be covered. Her death sentence is for accidentally killing a guard during a previous escape attempt. All her subsequent attempts to escape have been so that she could see her sister one last time before she dies.

The theme this time is then sisterhood as the two women fill in the missing half for the other and bond in their shared misuse at the hands of the justice system. Nami becomes determined to save Sayuri in the way she couldn’t save Yumi, but her struggle eventually takes on a larger dimension in keeping with those of the previous films as she tries to get revenge for Sayuri too after discovering that her death sentence was partly handed down by the murderous politician trying to tidy up loose ends as he plans career advancement with the aid of his entire amoral aide, Naruse (Tomorowo Taguchi). Escaping from the prison, she literally and symbolically frees all of the women who then take their own revenge on the sadistic warden.

For all of its seriousness, the film does have its faintly ridiculous qualities such as Nami’s use of electrical wiring as a defibrillator that allows her to resuscitate Sayuri after she’s hanged by the warden at the politician’s instigation. She later uses these same wires ripped from the wall to electrocute the warden’s bruiser male guard though it’s Sayuri who hot wires the prison van so they can escape. Eventually, she’s hunted down by a man with a crossbow and in a nod to the original trilogy, stabs him in the eye. Still, with her own revenge still in progress, Nami effectively avenges all her sisters while fighting for justice. Tracking down the videotape Sayuri had hidden proving the politician’s guilt, she eventually exposes him along with all his corruption bringing down the complex network that had extended out into the prison and trapped so many other women. Now a fugitive, Nami chases the one-armed man and has once again become an avenger of women bringing justice to those failed by an inherently corrupt and misogynistic justice system.