Mathieu Bellamont's mother was murdered by Lucien Lachance of the Dark Brotherhood when Mathieu was a child. He was driven insane by the sight of her severed head and vowed revenge on the Dark Brotherhood. He devised a complex and structured plan to bring it down.
First, he killed his father, the one who had prayed to the Night Mother for the death of his wife. Lachance took interest in him and invited him into the Brotherhood. Bellamont carried his mother's head with him throughout the course of his plan, until he took up residence in the Anvil Lighthouse basement, where he set up a small shrine with candles and the head in the middle. It was this same recluse that he brought the dead bodies of murdered Brotherhood members to be burnt.
- Mathieu and his "mother" may be a reference to the "Friday the 13th" series, where the killer, Jason Voorhees, who lives in a remote area with his Mother's severed head on an altar, takes revenge on the counselors of a summer camp for the death of his mother, which is similar to Mathieu taking revenge on the Dark Brotherhood.