Mary Shepherd-Sunderland is a key character in Silent Hill 2, although she is not directly encountered in the game until later on. She is the wife of the protagonist, James Sunderland, and her backstory is central to the game's plot and themes. At the start of the game, James receives a letter from Mary, which is strange because she had passed away from a long illness three years prior. This letter serves as the primary motivation for James to travel to the town of Silent Hill, where he believes he might find her.

Through flashbacks and James's recollections, it is revealed that Mary suffered from a debilitating illness, which caused much emotional strain on their marriage. Despite this, James had a deep, complicated love for her. However, Mary's death is marked by unresolved feelings of guilt, anger, and sadness, which are explored as James journeys through Silent Hill.

As the game progresses, it becomes clear that Mary's presence—and the letter—is a manifestation of James’s guilt and psyche. The psychological horror of Silent Hill 2 is rooted in these emotional struggles, with Mary's character symbolizing not just James's memories of her, but also his internal conflict and the consequences of his past actions.