No melody ever sang more clearly of the sea; no melody was ever less like a sailor's chanty. I have quoted words and tune in full (_f_). The words set the drama a-going; out of the phrase marked (_g_) the main body of the music of the first scene is spun. Isolda very naturally thinks an insult is aimed at herself: it is the spark that sets a light to the explosive material that has been accumulating in her heart for heaven knows how long. She curses the ship, Tristan, and every one concerned in the conspiracy that is to rob her of the man she loves and hand her over as a slave to the old man she has never seen. Brangaena, her maid, scared out of her wits, begs to know the truth; Isolda screams for air, which she assuredly seems to need; the curtains at the back of her pavilion are opened, and there, on the stern of the vessel, stands Tristan, the enemy whom she loves. From the masthead comes again the sailor's song. This time it does not immediately arouse Isolda to fury; for now her purpose is set--to kill Tristan: take her revenge and end her own life of misery. "Once beloved, now removed, brave and bright, coward knight. Death-devoted head, death-devoted heart," she sings, gazing at Tristan; and at the last words we hear the tremendous death-or murder-theme (_h_), a theme whose sinister meaning is afterwards unfolded. She sends Brangaena to order Tristan to come into her tent. He bitterly avoids understanding her meaning; Brangaena becomes more urgent; Kurvenal, Tristan's servant, a faithful watch-dog, asks to be allowed to reply; Tristan says he can. Kurvenal bellows out a song praising Tristan as the heroic slayer of Isolda's betrothed, Morold. Brangaena precipitately retreats and closes the curtains; Isolda and she face one another in the tent, the second nearly prostrate with dismay, the first boiling with wrath and shame at the insult hurled at her. She now tells Brangaena the whole of the preceding history--her nursing of Tristan and his monstrous treatment of her--and finishes with another curse. Brangaena tries to soothe her; Isolda, outwardly quietened, inwardly is planning how to carry out her purpose; Brangaena unknowingly suggests the means. "In that casket is a love potion: drink that, you will love your aged bridegroom and be happy once again." She opens the casket; "not that phial," says Isolda, "the other." The poison motive (_c_) sounds under the agitated upper strings: "the deadly draught," Brangaena shrieks: at this point the shouting of the sailors is heard as they begin to shorten sail; Kurvenal enters brusquely and bellows at Isolda the order to prepare to land. She refuses to move until Tristan has come in to ask her pardon "for trespass black and base." Here she begins to speak in terrible double-meanings: it is not Tristan's discourtesy on the voyage he must apologise for, but the more tragic occurrences leading up to his bearing her away to Cornwall. She orders Brangaena to prepare the draught, and awaits her