They hear Siegfried’s horn outside and the great hero arrives. Siegfried asks Hagen whether he knows him. Of course, Hagen does. Siegfried is carrying the magic tarn helmet which allows a person to change their shape or become invisible. Siegfried, however, does not know what the tarn helmet can do, and Hagen has to explain it to him. Gutrune appears and offers Siegfried a drink. It is the potion which is going to make him forget any other woman. He drinks to the health of Brünnhilde. As soon as he has drunk it he looks at Gutrune and is in love with her. He agrees to marry her, and he agrees to get a wife for Gunther. Hagen tells him about Brünnhilde on the rock. Siegfried has forgotten about her. He agrees to put on the tarn helmet and disguise himself as Gunther and to go and get Brünnhilde. He goes off, leaving Hagen guarding the palace.