As part of his costume, the Plague Doctor wears a porcelain mask with a beak. The mask obscures his face and symbolizes how the Plague Doctor often withholds information from Aiden. There are many important facts about the game and Aiden’s history that the Plague Doctor only shares with Aiden very late in the plot, leaving Aiden frustrated. For much of the novel, Aiden is confused and cannot access much of the information he wants, in the same way that he can’t see the Plague Doctor’s face. Even then, the Plague Doctor warns that “If I start telling you things that you shouldn’t know, there’ll be repercussions” (383). While the mask symbolizes the Plague Doctor’s guardedness and secrecy, his removal of the mask symbolizes an attempt at total trust and transparency. Just before he tells Aiden about Anna’s violent past, the Plague Doctor both removes his mask and tells Aiden his true name, explaining that “I need you to see my face and hear my voice, and know that what I’m telling you is the absolute truth. I can’t have you doubting me anymore” (385). While the Plague Doctor’s mask and removal of that mask symbolize secrecy and transparency, the presence of the mask also hints at the theme that virtually all of the characters are hiding something, whether they actually wear a mask or not.