Margot Cassity was a member of the wealthy Cassity family.
She used to be fat as a kid. Before Carl got married to Alice, he hooked up with Margot. She made a deal with Crowley believing money would make her family happy. She ran off before her older sister's wedding to live in Paris.
Following Carl's death, she returned home from Paris. One night at dinner, the history between her and Carl was revealed, much to Alice's shock. But she claims that it was before their marriage. She and Noah go out into the woods to hunt the animal responsible for Carl's death. She gets lost and was killed by the hellhound.