Possession

• Special effects artist Carlo Rambaldi, who built the film's wet, octopus-like creature, went on to win Oscars for Alien (1979) and E.T. the Extra-Terrestrial the following year (1982).
• Isabelle Adjani won Best Actress at the 1981 Cannes Film Festival for playing both Anna and her double Helen -- the same year she also won for Quartet, making her the only performer in Cannes history to take Best Actress for two films at once.
• The film was branded a 'video nasty' in the UK; the uncut version wasn't legally available there until the BBFC passed it in 1999.
• Director Andrzej Zulawski wrote the screenplay while going through a bitter divorce from actress Malgorzata Braunek, and much of Mark and Anna's dialogue was pulled from real arguments the two had.
• Shooting took place on location in Kreuzberg, West Berlin, right up against the Berlin Wall; the film competed for the Palme d'Or at Cannes that year, which went to fellow Pole Andrzej Wajda's Man of Iron.
• Sam Neill later said filming the scene where he slaps Adjani was 'the most distressing thing' he's ever done on camera, adding there were 'casualties' by the end of the shoot -- Adjani has said the role took her years to shake.

The creature is Anna's authentic self -- the woman Mark's surveillance-state masculinity refuses to see. She literally builds a better version of him from scratch because the original is a hollow spy. The doppelganger isn't the monster; Mark always was.

Both spouses are operatives, and the marriage was always a Cold War cover. Mark's 'assignment' and Anna's mystic lover Heinrich are parallel deployments. The Berlin setting isn't backdrop -- it's the story. Their domestic collapse mirrors the Wall's partition, and the creature is what happens when a cover identity breeds its own truth.

Bob is the creature's true progeny, not Mark's. The boy's final act -- locking himself in the bathroom and drowning himself the moment Helen opens the door to his father's double -- mirrors Anna's subway convulsion, suggesting he inherited whatever she was channeling. The film's real subject is generational transmission: the monster doesn't die, it just moves on to the next home.

Mark comes home from a shadowy overseas assignment to find his wife Anna wants out. She confesses to an affair with a preening mystic named Heinrich, but that's not the real problem — in a rotting apartment in Kreuzberg, Anna is nursing a pulsating, tentacled thing, feeding it the men who get too close (including the detective Mark hires to tail her) until it grows into a wet, green-eyed copy of Mark himself. While Anna spirals, Mark falls for Helen, their son Bob's schoolteacher and Anna's exact double, played by the same actress. The custody fight over Bob turns into a body count against the backdrop of a divided Cold War Berlin. Cornered by police outside Anna's apartment, she shoots herself with Mark's gun as he dies in the same hail of bullets. The creature-double slips away and knocks on Helen's door. As she answers it, Bob locks himself in the bathroom and drowns himself in the tub while sirens and explosions rip through the city outside.