[3][4] It was directed by Emma Sullivan and filmed in Copenhagen, Denmark.

[5][6] Before a subsequent release, Netflix, Plus Pictures and Sullivan agreed to re-edit the film to remove those participants who did not wish to appear.

[8] In 2016, Emma Sullivan, an Australian filmmaker began documenting amateur inventor Peter Madsen.

One year in, Madsen murdered Swedish freelance journalist Kim Wall aboard his homemade submarine.

[9] The version that premiered at Sundance festival holds a 100% on Rotten Tomatoes.