Harry Potter and the Half-Blood Prince
by J.K. Rowling
An officer employed by the Department of Magical Law Enforcement, he encounters the Gaunt family when he is sent to investigate an incident in which Morfin Gaunt used magic against a Muggle, Tom Riddle, Sr. We meet him in Chapter 10 via a memory of his that Dumbledore has procured. He is a good man who stands his ground, even in the face of Marvolo Gaunt's irascible and malicious behavior. He tries to protect Merope while he is there, noticing the abuse she receives from her father and brother.