A brilliant but troubled CEO of ITC, the company that developed advanced time-travel technology. He is depicted as the antagonist with a disregard for human life and a stereotypical evil genius demeanor.

A strong, handsome assistant professor of history at Yale and second-in-command at the Dordogne dig. Passionate about experimental history, he is skilled in medieval languages and practices.

A young history graduate student with a background in architecture and climbing, whose skills are invaluable during the archaeological dig and the adventures in the 14th century.

A 24-year-old history graduate student specializing in medieval mills whose close relationship with Professor Johnston is notable. He grows into a braver and stronger character over the course of the story.

A cautious graduate student and project technologist at the Dordogne dig with a deep knowledge of physics. He is wary of the new technology and skeptical about its safety.

Senior ITC executives; Gordon has a military background and a knack for making Doniger's visions reality, while Kramer is a lawyer with a closer relationship to Doniger. Both play roles in handling the company's ethical challenges.

An English knight known for his bad temper who controls Castelgard and La Roque in 1357, accompanied by his knights. Notably aggressive and paranoid in the ongoing conflict with Arnaut de Cervole.

A mercenary known as "The Archpriest," challenging Sir Oliver's control with the help of his supporters. Involved in the conflict and strategic maneuvers during the time period depicted.