In a dark dimension beyond the known planes of existence, the Chained God thirsts for freedom. Infusing his will into the residue of a long-dead universe—scarlet liquid shot through with veins of silver and flecks of gold—he sends this liquid crystal between worlds to prepare his way. But his will is not the only force that drives the Voidharrow. Imbued with the power of the Voidharrow, the dragon Vestapalk creates a horde of demonic minions to spread the Abyssal Plague across the Nentir Vale. But the threat is not contained within a single world: Faerûn and Athas must contend with their own outbreaks of tainted demons and virulent plague. Will the Voidharrow consume the multiverse? Will the Chained God break free? Or will the heroes of the age put a stop to the Abyssal Plague?

It is a time of magic and monsters, a time when only a few scattered points of light glow with stubborn determination amid a rising tide of shadows. It is a time when only the bravest heroes dare tread the wild of the unknown… About a century ago, the collapse of Nerath, the last empire of the world, ushered in a dark age that continues to this day, the peace and prosperity of the past seemingly lost forever. However, even those fabled days weren’t without a few blemishes. One of these was Emperor Magroth the First, a tyrant and a conqueror; cruel, ambitious, filled with delusions of grandeur and dreams of destiny, and more than a bit insane. During Magroth’s reign, rumors of necromancy and demon worship were rampant, but the truth was far worse. Thanks to deals he made, pacts he agreed to, and rituals he performed, death was not the end Emperor Magroth. Instead, a piece of him was drawn into the Shadowfell where he became the ruler of a domain of dead. From this vantage, the old king prepared for his return—and the new empire he would forge from the ruins of old. Now Magroth has made a new deal with Orcus, the Demon Prince of Undeath, that frees him from his eternal prison for a year and a day. In that time, Magroth must re-establish his ancient kingdom while also accomplishing a series of terrible tasks for Orcus. To this end, Magroth’s plans intersect with two other threats that are rising in the world. Where these threats meet, the world shudders. And it falls to our heroes to keep the fragile lights of civilization burning for another day