Who is Randolph Pethering from The Moor: A Mary Russell Novel and what is their importance?

Randolph Pethering travels to Baring-Gould's house in order to convince him to help with his research. His greatest desire is to be a scholar, and Pethering claims to be a teacher...... in reality, he is not. When he goes out in search of Lady Howard's coach, he is killed by Ketteridge, who proceeds to dump his body in a pond near Baring-Gould's house. Russell discovers the body.