Following close on the heels of The Mark of Nerath, Don Bassingthwaite picks up the action and takes the characters into the eye of a new kind of Dungeons & Dragons® adventure... Imprisoned in the void of a ruined universe by vengeful gods, Tharizdun—the Chained God, the Elder Elemental Eye—shares his exile with the Progenitor, a pool of liquid crystal that is all that remains of the Abyss that destroyed his universe. Enter our heroes Albanon, Shara and Uldane—all three adventurers readers will know from The Mark of Nerath. They thought their quests were over and done with, but danger still burns like the embers of a smoldering fire in the tall grass. The Progenitor was locked safely away, guarded by Albanon’s dead master, but early on our heroes realize it was stolen and released in the presence of the green dragon Vestapalk as he fell at Shara’s sword. Now, alerted to the danger of the liquid crystal by a mysterious cleric who claims allegiance to an order that has protected the substance for time immemorial, they must go in search of the dragon’s body, to ensure his demise has not been exaggerated. What they discover has consequences that could change the world...

Following directly in the wake of The Temple of Yellow Skulls, our heroes face the totality of the destructive and pestilent forces presented by the Abyssal Plague. The disease of the liquid crystal Voidharrow spreads throughout the land, transforming unsuspecting creatures into plague demons. Shara, Uldane, and the unlikely drow hero Valmaggar join forces with Tempest and Rohgar from The Mark Of Nerath, and together they set out in search of the green dragon Vestapalk, or the creature Vestapalk has become—the patient zero of this abyssal plague. Meanwhile, Albanon and the mysterious cleric Kri Redshal—the last remaining member of the Order of Vigilance, an order dedicated to guarding the Voidharrow—go in search of answers to the disease that sweeps the land. While their search takes them deep into the heart of the darkness that is enveloping the land, the answers they find are truly in need of new questions. As they become aware of the true scale of the tragedy at hand, they see the forces behind them are more powerful than they had ever dreamed, and perhaps more seductive.

In the aftermath of the plague demons' attack on Fallcrest, Roghar's inspiring optimism has played a significant role in the rebuilding of the town. Albanon, meanwhile, has not recovered so well. Tormented by his experiences and his near-transformations first by Vestapalk then by Kri, he has retreated to Moorin's tower, where he immerses himself in books. He is the last member of the Order of Vigilance, touched by both the Voidharrow and Tharizdun—he feels as if he stands on the brink of madness. The Nentir Vale has been ravaged by the abyssal plague and the plague demons. The area is lawless and suspicions run rampant. Only safe as long as they hide, the heroes scout as close as they dare. But with Vestapalk growing ever-stronger and plague demons on the rise, they know they have to act soon. The world cannot afford to wait any longer. As they journey toward the greatest concentration of demons they learn they are on the right path and they gain an ally. Kri, believed dead, resurfaces with wisdom garnered from the Chained God. It seems even Tharizdun himself is against Vestapalk.