'What He Did' is the story of psychologist and author Jens Michael Schau, who in 1988 killed his boyfriend of 13 years, Christian Kampmann, in a fit of jealousy. Kampmann was at the peak of his literary career at the time, and had gone to the small Danish island with Schau to write the continuation of the beloved television series 'Matador'. During this stay something went wrong - but what and why?