Watch full movie online. Lesson 9 is a short film about the loss of a lover to insanity. Part horror story, noir-like mystery and disaster film, Lesson 9 weaves together shards of a narrative that has been shattered like excerpts from the journal of a lover gone mad. A disaster movie after the disaster, the film uses three different definitions of possession to form its thematic structure and to explore love, loss, sexuality and insanity.