The Farewell
The gardens of the castle. Normanno, the right-hand retainer of the lord of the castle, speaks of how he will restore the family’s honour. Then Enrico, lord of the castle lets slip that he wants to destroy his arch-enemy Edgardo and have his sister Lucia enter into a tactical marriage with Lord Arturo, but that Lucia will not consent.
Lucia’s instructor, Raimondo, explains that she is “weeping thinking of her mother who has passed away”, to which Normanno says, “She has a lover”, and reveals that it is Enrico’s arch-enemy Edgardo. Enrico pales with anger, and people inform him that “Edgardo has appeared for a moment”. Enrico’s rage builds.
Evening at the castle. Lucia waits in the garden for her lover. She says she has seen a ghost by the fountain, thus frightening her handmaid, Alisa. Edgardo appears, and tells Lucia that he must make an urgent trip to France. This saddens Lucia, but he asks her to pledge her undying love for him. The exchange rings, and Lucia bids him farewell.

The Engagement
Enrico’s house. Normanno tells his lord that he has prepared a counterfeit letter as if from Edgardo stating that he has given his heart to another woman. Lucia appears. Her brother orders her to marry Arturo for the sake of the family, but she replies that she has pledged her love to another. However, she is shaken by reading the counterfeit letter, and calls on divine help. Raimondo talks to Lucia and persuader her that her lover is unfaithful.
A crowd awaits the bridegroom in the great hall of the palace. Arturo appears. Enrico goes to greet him, and Lucia also appears attired as a bride. In a daze, she signs the marriage covenant as ordered. At the moment, Edgardo suddenly appears. Arturo and Enrico stand in his way, but Raimondo comes between them and shows the marriage covenant. On seeing it, Edgardo really believes Lucia has betrayed him and grabs the ring from her finger. The whole castle goes into an uproar.

A room in the tower Edgardo lives in. In the midst of a storm, Enrico appears before the troubled Edgardo. The two challenge each other to a dual.
There is a banquet going on at Enrico’s castle, where Raimondo appears and tells everyone that Lucia has lost her mind and killed Arturo. Before long, Lucia appears covered in blood crying Edgardo’s name and mumbling that she still loves h,. On seeing her in this state, Enrico and Raimondo are at a loss. Lucia collapses.
The scene changes to Edgardo standing motionless before the graves of his forebears, mulling his lover’s treachery. He is startled by the appearance of others singing “Oh, forlorn maiden”, and asks who they are weeping for. Raimondo appears and tells him of Lucia’s death. The despairing Edgardo prays “May we be wedded in heaven”, and follows Lucia into death.

Time: Early 18th century
Place: Scotland

Act 1

Scene 1: The gardens of Ravenswood Castle

Normanno, captain of the castle guard, and other retainers are searching for an intruder. He tells Enrico that he believes that the man is Edgardo of Ravenswood, and that he comes to the castle to meet Enrico's sister, Lucia. It is confirmed that Edgardo is indeed the intruder. Enrico reaffirms his hatred for the Ravenswood family and his determination to end the relationship.

Scene 2: By a fountain at the entrance to the park, beside the castle

Lucia waits for Edgardo. In her famous aria "Regnava nel silenzio", Lucia tells her maid Alisa that she has seen the ghost of a girl killed on the very same spot by a jealous Ravenswood ancestor. Alisa tells Lucia that the apparition is a warning and that she must give up her love for Edgardo. Edgardo enters; for political reasons, he must leave immediately for France. He hopes to make his peace with Enrico and marry Lucia. Lucia tells him this is impossible, and instead they take a sworn vow of marriage and exchange rings. Edgardo leaves.

Act 2

Scene 1: Lord Ashton's apartments

Preparations have been made for the imminent wedding of Lucia to Arturo. Enrico worries about whether Lucia will really submit to the wedding. He shows his sister a forged letter seemingly proving that Edgardo has forgotten her and taken a new lover. Enrico leaves Lucia to further persuasion, this time by Raimondo, Lucia's chaplain and tutor, that she should renounce her vow to Edgardo, for the good of the family, and marry Arturo.

Scene 2: A hall in the castle

Arturo arrives for the marriage. Lucia acts strangely, but Enrico explains that this is due to the death of her mother. Arturo signs the marriage contract, followed reluctantly by Lucia. At that point Edgardo suddenly appears in the hall. Raimondo prevents a fight, but he shows Edgardo Lucia's signature on the marriage contract. Edgardo curses her, demanding that they return their rings to each other. He tramples his ring on the ground, before being forced out of the castle.

Act 3

Scene 1: Wolfcrag

Enrico visits Edgardo to challenge him to a duel. He tells him that Lucia is already enjoying her bridal bed. Edgardo agrees to fight him. They will meet later by the graveyard of the Ravenswoods, near the Wolf's Crag.

Scene 2: A Hall

Raimondo interrupts the marriage celebrations to tell the guests that Lucia has gone mad and killed her bridegroom Arturo. Lucia enters. In the aria "Il dolce suono" she imagines being with Edgardo, soon to be happily married. Enrico enters and at first threatens Lucia but later softens when he realizes her condition. Lucia collapses. Raimondo blames Normanno for precipitating the whole tragedy.

Scene 3: The graveyard of the Ravenswood family

Edgardo is resolved to kill himself on Enrico's sword. He learns that Lucia is dying and then Raimondo comes to tell him that she has already died. Edgardo stabs himself with a dagger, hoping to be reunited with Lucia in heaven.