Complete story — includes the ending
Queen Mary's wedding to Don Carlos approaches. Don Carlos secretly regains his memory, and seeks his revenge on Mary by asking for the crown matrimonial of Scotland. Mary is suspicious and asks Gideon for help; he learns that Don Carlos plans to assassinate Mary after the wedding. Queen Mary tricks Don Carlos into confessing his intentions to all, and the wedding is cancelled. Queen Mary also learns that Gideon is being blackmailed by Queen Elizabeth, who is holding Lord Gideon's daughter hostage. Queen Elizabeth is pregnant with Robert's child, so she pressures Robert to divorce Amy and marry her. When Lady Amy learns of this, she goes stark mad and frames Robert for murder by killing herself. Queen Catherine continues her affair with Christophe and has him elevated to a member of the King's Guard. Princess Claude and Leith consummate their relationship. Soon afterward Narcisse announces that Claude will be married off to a wealthy Duke, so her dowry can be used to pay some of the French crown's debts. Delphine fears that the murderer's killing instinct is inside her, and the murderer kills again.
Sources and content license
Source and revision history · Adapted from Wikipedia contributors, Reign season 3. HTML formatting and reference markers removed. · Content license