Man, when Hong Kong filmmakers make a video nasty in no way do they fuck around.

The first category III rated film in Hong Kong, this movie sets out to document the World War II atrocities committed by the Japanese at Unit 731, the secret biological weapons experimentation unit of the Imperial Japanese Army during World War II.

Of course, by proclaiming this as educational, it’s equally about watching Chinese and Siberian prisoners being horribly tortured and killed.

Director Mou Tun-fei went to a film school that had so little money that its graduates could only learn from watching and never getting to make their own movies. The style of his early work is based on the Italian neorealist movement and while he made numerous movies for Shaw Brothers*, he was the first Taiwanese director to make movies on the mainland. After this film — he was working on a children’s kung fu movie when the idea came to him — Tun-Fei would make two more movies, the pornographic Trilogy of Lust and the sequel to this movie, Black Sun: The Nanking Massacre.

The main goal of the facility is to learn how to weaponize the bubonic play and destroy China. Somehow, this also means capturing children and operating on their organs while they’re still alive and freezing the hands of people and shattering them with hammers. There’s also a harrowing scene where a cat is attacked by rats and then prisoners are crucified and a flea bomb is meant to be dropped on them before they escape and are run down.

If that doesn’t bother you enough, the effects in this movie include the corpse of a child and the arms of another corpse, this time held by the director’s niece, the only actress brave enough to stand in the cold holding the arms of a dead man.

This is the kind of movie that I don’t think I could make it through again, but for the sake of the sight, my need to see every infamous movie and just plain morbid curiosity, I made it.

*His 1980 film for the studio, Lost Souls, has been compared to Pasolini’s Salò.