Plot summary
Queen Catherine believes that Narcisse will help her become regent, especially when he makes her leave her servant lover, Christophe (Nathaniel Middleton), for him. However on the day of the vote, Cardinal Morel (Blair Williams) presents a blackened liver that supposedly belonged to Francis, "proving" that the king was poisoned and Catherine the likely culprit. Narcisse, with the council's support, is declared regent. Bash and Delphine expect the killer they are investigating to attack Greer next, but the killer attacks Delphine instead. Delphine is spared when she temporarily absorbs the killer's murderous instinct, but is unable to identify him.
Mary and Don Carlos are close to an engagement, but are stalled by Gideon Blackburn, who claims that Don Carlos has a "dark secret". Upon investigation, Queen Mary learns that Don Carlos is a masochist who desires to be flogged. Mary is reluctant, but she and Catherine stage a secret flogging session for Don Carlos which ends badly — Don Carlos falls and cracks his skull, but survives and wanders out of the room.
Credits
Adapted from Wikipedia contributors, Reign season 3. HTML formatting and reference markers removed.