After a long battle, Lord Henry Ashton of Lammermoor has become dominant over Edgardo of Ravenswood. Meanwhile, Edgardo and Lord Ashton's sister, Lucia, have fallen madly in love and have agreed to be wed in the future. Lord Ashton, though, is arranging a marriage between Lucia and Lord Arturo Bucklaw. After, Edgardo goes abroad, Lucia is shown a forged letter stating that Edgardo has found another woman. Crying, she agrees to sign the marriage contract with Lord Bucklaw. Soon though, Edgardo returns and challenges Bucklaw to a duel. Before bloodshed occurs however, Edgardo witnesses Lucia's signature on the marriage contract, curses her, and escapes. Distraught, Lucia takes up a knife and murders Arturo.