"It is certain that we face the demon queen, Andariel..." -Deckard Cain Sisters to the Slaughter is the sixth and final quest of Act I in Diablo II. As the ultimate quest in Act I, Sisters to the Slaughter will require that you seek out and destroy Andariel, the Maiden of Anguish. Though your objective has likely been assumed while playing through Act I, it will be Deckard Cain who actually assigns this quest. Defeating Andariel grants access to Act II and the deserts of Aranoch.