Copyright © 2025 BBC. The BBC is not responsible for the content of external sites. Read about our approach to external linking.

Merlin is shocked to the core when he discovers the only way to restore the equilibrium requires a sacrifice of unimaginable proportions.

who took his duties as Merlin's mentor and Camelot's Court Physician seriously. Ironically, he played a medical role in Doctor Who as well, appearing as Dr. Constantine in the Series 1 episodes ...