A character exclusive to the story, Sienna is initially portrayed as a close ally to Robert Langdon. Her deep understanding of the story's central crisis and complex past conceal deeper motivations and make her a pivotal figure in the unfolding narrative.

The head of the World Health Organization, Sinskey is depicted as an influential figure tackling global health issues. Her professional history and interactions with the primary antagonist provide critical insights into the story's conflict.

The leader of the Consortium, an independent security firm with covert and extralegal operations. His pragmatic, morally indifferent nature contributes heavily to the narrative tension, making him a significant antagonist in the story.

An agent of the World Health Organization tasked with capturing Langdon, Brüder represents a by-the-book, authoritative force. His pursuit of Langdon throughout the story adds urgency and serves as a central plot driver.

The story's primary antagonist, Zobrist is depicted posthumously through his groundbreaking yet controversial research. His earlier interactions with Sinskey and his philosophical ideas are central to the plot and provoke much of the mystery and suspense in the story.