Question: The fictional character in J. K. Rowling's "Harry Potter" series Severus Snape becomes a double-agent on behalf of this secret organisation to fight Voldemort and his followers known as what?
Sentence (from "Severus Snape"): Though philosophically attracted to the Dark Arts and Lord Voldemort's ideology of wizard supremacy, Snape's love for Muggle-born Lily Evans, Harry's mother, eventually compels him to defect from the Death Eaters.
Relevant evidence: No