Lisa enters Rodolfo's room to see if all is well. She reveals that his identity is known to all as Rodolfo, the long-lost son of the count. She advises him that the village is preparing a formal welcome; meanwhile she wishes to be the first to pay her respects. She is flattered when he begins a flirtation with her, but runs out at the sound of people approaching, dropping her handkerchief which the Count picks up. He sees the approaching phantom who he recognises as Amina. She enters the room, walking in her sleep, all the while calling for Elvino and asking where he is. Realising that her nocturnal wanderings have given rise to the story of the village phantom, Rodolfo is about to take advantage of her helpless state. But then he is struck by her obvious innocence and refrains: (Scene: first Rodolfo: / "God! What am I doing?"; then, separately, Amina: / "How happy all the people are, accompanying us to the church"; then together.) As Amina continues her sleepwalk, Rodolfo hears the sound of people approaching and, with no other way out, he climbs out of the window.