On 17 August 2008, eighteen year old Morne Harmse arrived at school in Krugersdorp. The slight pupil, described by his classmates as quiet, well mannered, and playful, then did something unthinkable. With accusations of Satanism, the idolisation of Heavy Metal bands like Slipknot, and the boy’s use of a Samurai sword - this is one of the most unusual killings ever committed. We investigate why it might have happened.