Wilhelm has brought Mignon and Lothario to a castle in Italy which he considers buying. There an old man watches over Mignon and prays for her recovery. Antonio relates how the castle's previous owner had gone mad after his wife had died of grief over the loss of their young daughter. Wilhelm decides to buy the castle for Mignon because it has so speeded her recovery. Mignon awakens and confesses to Wilhelm of her love for this strangely familiar place. He finally realizes that he loves her deeply and resists Philine's attempts to win him back. Lothario re-enters and informs the couple that he is the owner of the castle and that returning here has restored his sanity. After reading a prayer found in a book in the house, Mignon realizes the she is his daughter Sperata. The three embrace happily.