Plot summary
Prince Charles's coronation is marred by the discovery of dead bodies in the castle, victims of the same murderer Bash has been tracking. With Christophe's help, Bash finds evidence that the castle butcher ( Christopher Jacot ) is responsible, and he is hanged. However, Catherine learns that Christophe is the true murderer, but he blackmails her into keeping his secret. Mary spends time with Gideon and his young daughter Agatha. There is some discussion of the proposal of Eric XIV of Sweden to marry Mary. Queen Mary learns that the Protestant preacher John Knox is leading the persecution of Catholics in Scotland, and calls upon the Vatican for help raising an army against him.
Elizabeth presses Lola for information on Queen Mary, but Lola refuses to comply. Instead Lola tells Elizabeth her new discovery that William has been paying courtesans to dress up as Elizabeth for his pleasure. Elizabeth uses this lead to uncover that William is in love with her and poisoned her, causing her miscarriage; she banishes him from court for good.
Credits
Adapted from Wikipedia contributors, Reign season 3. HTML formatting and reference markers removed.