Deckard Cain is the last of the Horadrim, the only surviving member of a mysterious and legendary order. Chosen by the archangel Tyrael, the Horadrim considered it their sacred duty to find and defeat the great embodiments of evil: Diablo - the Lord of Terror, Mephisto - the Lord of Hatred and Baal - the Lord of Destruction. But that was many, many years ago. As the years passed, the power of the Horadrim Order weakened and they fell into obscurity. All that remains of them - the history of the great past, battle tactics and wisdom - is concentrated in the hands of one old man. A man preoccupied with the dark rumors that float in the air, tales of the awakening of an ancient evil, mutterings of an invasion of demons that have already begun to tear the earth apart. Amid the mounting horror, Deckard Cain discovers something startling that could bring either salvation... or destruction to the mortal world. It turns out that other adepts of the Horadrim order still exist. Deckard must figure out where they have been so far and why they are hiding from one of their own. In his search for his lost brothers in the order, Cain finds his most unlikely ally - eight-year-old Leah, whom many suspect of being cursed by demons. What secret is the girl hiding? How is this mystery connected to the prophecies of the End of Days? And if other Horadrim do exist, will they be able to withstand oblivion? These are the questions Deckard Cain must answer... before it's too late.