On August 10th, 2017, Freelance Journalist Kim wall joined Danish inventor Peter Madsen on his Submarine, the UC3 Nautilus, with the intent of interviewing him. Several hours after they were expected to return, Kim's boyfriend reported her missing. A search ensued for Kim, Peter, and the missing submarine.

The next day, Madsen was rescued from the sinking sub, but Kim was nowhere to be found. What followed was the most infamous criminal investigation in the history of Denmark.