Detailed Instructions: In this task, you are given a context paragraph, a question based on that and corresponding answer of a question. Your task is to generate supporting fact/knowledge from context paragraph which helps in answering a given question.
Q: Severus Snape is a fictional character in J. K. Rowling's "Harry Potter" series. An exceptionally skilful wizard, his coldly sarcastic and controlled exterior conceals deep emotions and anguish. A Professor at Hogwarts School of Witchcraft and Wizardry, Snape is hostile to the series' protagonist, Harry, the moment he sets foot in Snape's classroom; this hostility is rooted in Harry's resemblance to Harry's father James, who bullied and harassed Snape during their time at Hogwarts. 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. Snape becomes a double-agent on behalf of Albus Dumbledore and the Order of the Phoenix, and protects Harry throughout the series. Question: Alan Sidney Patrick Rickman was an English actor who gained wider notice for his film performance as a fictional character in a film series who becomes a double-agen on behalf of who?  Answer: Albus Dumbledore
A:
Severus Snape is a fictional character in J. K. Rowlings Harry Potter series.