|“|| The shadow legacy of Erevis Cale lives on even as his old foe Mephistopheles seeks to stamp it out at any cost. Cale's son Vasen—unmoored in time by the god Mask—has thus far been shielded from the archdevil's dark schemes, alone among the servants of the Lord of Light who have raised him since birth.
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Putting the pieces into place, Mask had sent Varra, the lover of Erevis Cale and pregnant with his child, into the future past the Spellplague. Varra is found by Derreg, son of Regg and brought to safety only to deliver her child, Vasen Cale, and then die during childbirth.
Vasen is raised under the faith of the newly revealed Amaunator, as a paladin. He lived his life as an escort to the faithful of Amaunator to the Abbey of the Rose, a temple veiled from the Shadovar that dominated Sembia. He also acted as protector to the Oracle, the simple son of Abelar Corrinthal. During an escort of pilgrims out of the valley, the Oracle sends away everyone, knowing the fate about to befall everyone.
Along with Orsin, a shadowalker that was accompanying the pilgrims, Vasen investigates signs of a struggle, only to find a village slaughtered by the hands of Sayeed and Zeeahd, brothers transformed by the Spellplague and on on a mission from Mephistopheles to find the son of Erevis Cale. They encounter Gerak, a hunter and former soldier, trying to help his wife who was infected by Zeeahd by a diabolical sludge. It is also revealed that the brothers were seeking the Oracle. With that, Gerak, Orsin, and Vasen head back to the abbey as quickly as they can.
The trio find the valley alight by several spined devils, which have accompanied Sayeed and Zeeahd. Fighting their way through the devils and Sayeed, Vasen makes his way to one of the towers in which Zeeahd is confronting the Oracle. The Oracle reveals that Vasen is the son of Erevis and then sacrifices himself just before Vasen reaches Zeeahd and his devils. Gerak and Orsin rejoin Vasen and escaped as Zeeahd transforms into a bone devil.
With the protection of the abbey gone, Brennus Tanthul, prince of the Shadovar, finds Vasen and quickly dispatch his forces. With the devils on their heels and now the Shadovar, Gerak, Orsin, and Vasen make their way to a pond Orsin previously identified as having some connection to his past life and Mask. The pond is now a portal and they all enter just before Brennus arrives to stop them.
The three find themselves in a part of the Shadowfell that Drasek Riven, with his sliver of Mask's divinity, connected with Cania, the realm ruled by Mephistopheles and the frozen prison of Erevis Cale. Riven provides a distraction for Mephistopheles and part of his forces while Gerak, Orsin, and Vasen find and release Erevis.
With Erevis now rescued they all teleport to Ordulin to stop Rivalen Tanthul, who also has a sliver of Mask's divinity and seeks to bring about Shar's will to destroy all of Toril. Rivalen has forced Sayeed into being the vessel from which the words to complete Shar's plan would be read. Rivalen teleports himself and Mephistopheles to Ordulin as well, bringing all the slivers of Mask to one place. Rivalen then forces Vasen to read the words on Sayeed's body, finishing the elements to finalize Shar's plan. Remembering the words of the Oracle and his dreams, Vasen stops Shar's Eye from pulling the divinity out of Riven and Mephistopheles. Erevis is able to cut the divinity from Riven, Mephistopheles, and Rivalen. Erevis feels it is his responsibility to take on the godhood, but Riven stops him and convinces him it would be better if he takes it.
During the conflict, Erevis and Riven's friend Magadon Kest had been piloting the floating Shadovar city of Sakkors towards Ordulin. With the mythallar that powers the city dying, Magadon leaves it on its course and flees the city. Sakkors bears down on Ordulin as Vasen, Erevis, Gerak, and Orsin leave Rivalen grappled by his revenge-seeking brother, Brennus, to be crushed by the city.
The novel was planned as the first book in the Cycle of Night trilogy, but instead it was published in the The Sundering Series. Paul S. Kemp has stated that it is a standalone novel that tells the whole story he intended to write in the "Cycle of Night" Trilogy.