Mary Oldrey is the wife of J. A. Oldrey and mother of Henry. She lived at the Villa in a countryside close to Dracula's Castle. When the Dark Lord was resurrected, the Villa was overrun by vampires and other evils.
Cornell encounters Mary from outside her bed chambers. He sees J. A. Oldrey, her husband, demanding she allow him into her room for a drink, which Mary refuses. Since J. A. Oldrey cannot open the door, he decides to attack Cornell instead. Cornell defeats J. A. Oldrey, who turns into a bat and flies away. Mary then allows Cornell inside and explains her situation to him. Although her husband is a vampire, Mary continues to love him. She also cares about her son, Henry, who is hiding in the maze garden and pleads Cornell to lead him out of the villa, where he can be safe. As a token of her gratitude, Mary gives Cornell the copper key and says that as long as Henry is safe, she has no regrets.
The exact fate of Mary is unknown. It is assumed that she died within her home sometime before Reinhardt and Carrie arrived. Other possibilities are that J. A. Oldrey got to her one day and transformed her into a vampire or that she committed suicide as she had explained to Cornell that "Rather than become a vampire, [she had] even thought of taking [her] own life."