On their way to ask the count to attest to Amina's innocence, the villagers rest in the woods and consider how they will express their support to him: (Chorus: Qui la selva è più folta ed ombrosa / "Here the wood is thick and dark").
Amina and Teresa arrive and are on a similar mission, but Amina is despondent, although Teresa encourages her daughter to continue.
They then see Elvino coming in the wood looking downcast and sad.
He continues to reject Amina, even when the townspeople come in with the news that the count says that she is innocent.
Elvino is not convinced and takes back the ring, though he is unable to tear her image from his heart: (Aria, then chorus: Ah!
Perché non posso odiarti, infedel, com'io vorrei! / "
Why cannot I despise you, faithless, as I should?")

Scene 2: The village, as in act 1
Lisa, Alessio, Elvino and the villagers are in the square.
Elvino declares that he will renew his vows and proceed to marry Lisa.
She is delighted.
As they are about to go to the church, Rodolfo enters and tries to explain that Amina is innocent because she did not come to his room awake – she is a somnambulist, a sleepwalker: (Duet, first Elvino Signor Conte, agli occhi miei / negar fede non poss'io / "I cannot deny, my lord, what my eyes have seen"; then Rodolfo V'han certuni che dormendo / "Certain people when they sleep go about as if awake".)
Elvino refuses to believe him and calls upon Lisa to leave, but at that moment Teresa begs the villagers to be quiet, because Amina has at last fallen into an exhausted sleep.

Learning of the impending marriage, Teresa confronts Lisa, who says that she has never been found alone in a man's room.
Teresa produces the handkerchief Lisa had dropped.
The Count is unwilling to say what he thinks of this, but continues to insist on Amina's virtue.
Elvino demands proof and Rodolfo, seeing the sleeping Amina walking across the high, dangerously unstable mill bridge, warns that to wake her would be fatal.
All watch as she relives her betrothal and her grief at Elvino's rejection, taking the withered flowers in her hand. (
Aria: Amina Ah!
non credea mirarti / sì presto estinto, o fiore / "I had not thought I would see you, dear flowers, perished so soon".)
Then as she reaches the other side safely, the distraught Elvino calls to her and she is taken into his arms.
Rodolfo hands him the ring which he places on her finger, at which time she awakens and is amazed by what has happened.
All rejoice.
In an aria finale, Amina expresses her joy: Ah!
non giunge uman pensiero / al contento ond'io son piena / "Human thought cannot conceive of the happiness that fills me".
On their way to ask the count to attest to Amina's innocence, the villagers rest in the woods and consider how they will express their support to him: (Chorus: Qui la selva è più folta ed ombrosa / "Here the wood is thick and dark"). Amina and Teresa arrive and are on a similar mission, but Amina is despondent, although Teresa encourages her daughter to continue. They then see Elvino coming in the wood looking downcast and sad. He continues to reject Amina, even when the townspeople come in with the news that the count says that she is innocent. Elvino is not convinced and takes back the ring, though he is unable to tear her image from his heart: (Aria, then chorus: Ah! Perché non posso odiarti, infedel, com'io vorrei! / "Why cannot I despise you, faithless, as I should?")
Scene 2: The village, as in act 1
Lisa, Alessio, Elvino and the villagers are in the square. Elvino declares that he will renew his vows and proceed to marry Lisa. She is delighted. As they are about to go to the church, Rodolfo enters and tries to explain that Amina is innocent because she did not come to his room awake – she is a somnambulist, a sleepwalker: (Duet, first Elvino Signor Conte, agli occhi miei / negar fede non poss'io / "I cannot deny, my lord, what my eyes have seen"; then Rodolfo V'han certuni che dormendo / "Certain people when they sleep go about as if awake".) Elvino refuses to believe him and calls upon Lisa to leave, but at that moment Teresa begs the villagers to be quiet, because Amina has at last fallen into an exhausted sleep.
Learning of the impending marriage, Teresa confronts Lisa, who says that she has never been found alone in a man's room. Teresa produces the handkerchief Lisa had dropped. The Count is unwilling to say what he thinks of this, but continues to insist on Amina's virtue. Elvino demands proof and Rodolfo, seeing the sleeping Amina walking across the high, dangerously unstable mill bridge, warns that to wake her would be fatal. All watch as she relives her betrothal and her grief at Elvino's rejection, taking the withered flowers in her hand. (Aria: Amina Ah! non credea mirarti / sì presto estinto, o fiore / "I had not thought I would see you, dear flowers, perished so soon".) Then as she reaches the other side safely, the distraught Elvino calls to her and she is taken into his arms. Rodolfo hands him the ring which he places on her finger, at which time she awakens and is amazed by what has happened. All rejoice. In an aria finale, Amina expresses her joy: Ah! non giunge uman pensiero / al contento ond'io son piena / "Human thought cannot conceive of the happiness that fills me".
La sonnambula