First Performed: 1835
Setting: Scotland, late 1700s
On a sunlit afternoon just outside of the Lammermoor Castle, there is a bit of frantic commotion. It is believed an intruder is running about the castle grounds. Lord Enrico, Lucia's brother, is approached by guardsman, Normanno, who tells him that he believes the intruder is Edgardo di Ravenswood, a family rival. Furious, Enrico knows why Edgardo is there - to see Lucia. Enrico's family is running out of funds and has made arrangements for Lucia to marry Lord Arturo in hopes to establish the family politically as well as financially. Lucia has remained stubborn and continues to see Edgardo "secretly," refusing to marry Arturo. Enrico vows to end their relationship.
Lucia and her handmaid, Alisa, are waiting in the graveyard next to her mother's tomb. Lucia is excited about her upcoming rendezvous with Edgardo. She recounts a legend that a girl was once killed by a Ravenswood man in the very spot they are waiting. Alisa warns Lucia that it is an omen and, if she were smart, should immediately break up with Edgardo and never see him again. Lucia tells Alisa that her love for Edgardo is stronger than any omen or apparition. When Egardo arrives, he tells Lucia that he must leave for France for political reasons, but before he departs, he wants to make peace with Enrico so that he can take Lucia's hand in marriage. Lucia instructs him not to speak with Enrico, since he will never change his mind. His hatred for the Ravenswood family runs too deep. He finally agrees to keep their love hidden. The two lovers exchange rings and vow themselves to each other before Edgardo leaves.
Within the castle, Enrico and Normanno plot a way to persuade Lucia to marry Lord Arturo. Enrico has scheduled the wedding ceremony to take place later that day and has already invited the guests. As Normanno exits to greet Lord Arturo, Lucia enters the room visibly upset. Enrico shows Lucia a forged letter from Edgardo stating that he has disavowed Lucia and taken the hand of another woman in marriage. Raimondo, Lucia's chaplain, chimes in and tells her that she should marry Arturo as it would make her deceased mother proud. After all, she would be saving the family from misfortune. He tells her that the sacrifice she makes here on earth will be greatly rewarded in heaven. Lucia, heartbroken, agrees to marry Arturo.
Downstairs in the great hall, the wedding ceremony is about to begin. A large crowd of family members and friends are awaiting anxiously. Lord Arturo promises to Enrico that the marriage will bring back prestige to his family and estate. Suddenly, Edgardo bursts through the doors. Having arrived home earlier than expected, he has heard that Lucia is about to marry Lord Arturo. When Raimondo establishes peace and swords are sheathed, Edgardo sees that Lucia has signed the wedding agreement. In a fit of rage, he throws his ring to the floor and curses Lucia. Lucia, unable to bear the pain, collapses to the floor. Edgardo is thrown out of the castle.
Edgardo is sitting near the Wolf's Crag tower within the cemetery, reflecting on the recent happenings. Enrico shows up and gloats to Edgardo that Lucia is enjoying her wedding bed. The two men, furious with one another, agree to a duel the following dawn.
Back in the great hall, Raimondo announces that Lucia has gone mad and killed her bridegroom, Arturo. The wedding festivities quickly come to a halt. Lucia appears and sings the opera's most famous aria, "Il dolce suono." Her eyes are empty as if no one is home. Unaware of what she has done, she sings of her love for Edgardo and cannot wait to marry him this day. When Enrico arrives, he scolds Lucia for what she has done. He finally backs down after he realizes that there is something severely wrong with her. In that moment, Lucia falls to the floor and breaths her last breath.
At dawn, Edgardo awaits his duel with Enrico. Saddened by Lucia's betrayal, he resolves his fate and will die by Enrico's sword. Guests of the wedding pass by Edgardo conversing with each other about Luica's death. As Edgardo is about to rush to the castle, Raimondo arrives to tell him the tragic news. Unable to live without her, Edgardo takes out his own sword and stabs himself. If he cannot be with her on earth, he will be with her in heaven.