In the second act occur the bridal ceremonies, prior to which, moved by Ortrud’s entreaties, Elsa promises to obtain a reprieve for Telramund from the sentence which has been pronounced against him.  At the same time Ortrud takes advantage of her success to instil doubts into Elsa’s mind as to her future happiness and the faithfulness of Lohengrin.

In the next scene, as the bridal cortege is about to enter the minster, Ortrud claims the right of precedence by virtue of her rank, and Telramund publicly accuses Lohengrin of sorcery.  The faith of Elsa, however, is not shaken.  The two conspirators are ordered to stand aside, the train enters the church, and Elsa and Lohengrin are united.

The third act opens in the bridal chamber.  The seeds of curiosity and distrust which Ortrud has sown in Elsa’s mind have ripened, and in spite of her conviction that it will end her happiness, she questions Lohengrin with increasing vehemence, at last openly demanding to know his secret.  At this juncture Telramund breaks into the apartment with four followers, intending to take the life of Lohengrin.  A single blow of the knight’s sword stretches him lifeless.  He then places Elsa in the charge of her ladies and orders them to take her to the presence of the King, whither he also repairs.  Compelled by his wife’s unfortunate rashness, he discloses himself as the son of Parsifal, Knight of the Holy Grail, and announces that he must now return to its guardianship.  His swan once more appears, and as he steps into the boat he bids Elsa an eternal farewell.  Before he sails away, however, Ortrud declares to the wondering crowd that the swan is Elsa’s brother, who has been bewitched by herself into this form, and would have been released but for Elsa’s curiosity.  Lohengrin at once disenchants the swan, and Gottfried appears and rushes into his sister’s arms.  A white dove flies through the air and takes the place of the swan, and Lohengrin sails away as Elsa dies in the embrace of her newly found brother.

The Vorspiel, or prelude, to the opera takes for its subject the descent of the Holy Grail, the mysterious symbol of the Christian faith, and the Grail motive is the key to the whole work.  The delicious harmonies which accompany its descent increase in warmth and power until the sacred mystery is revealed to human eyes, and then die away to a pianissimo, and gradually disappear as the angels bearing the holy vessel return to their celestial abode.  The curtain rises upon a meadow on the banks of the Scheldt, showing King Henry surrounded by his vassals and retainers.  After their choral declaration of allegiance, Telramund, in a long declamatory scena of great power ("Zum Sterben kam der Herzog von Brabant"), tells the story of the troubles in Brabant, and impeaches Elsa.  At the King’s command, Elsa appears, and in a melodious utterance of extreme simplicity and sweetness, which is called the dream motive ("Einsam in trueben Tagen"),