She quickly gains the help of Chet Starfinder, a human explorer who has been in the Nowhere for 170 years, and deduces that he is actually Commander Spears, M-Bot's previous owner.

While she sleeps, Spensa is able to commune with Jorgen and eavesdrop on Winzik and Brade, who she finds successfully making a deal with the delvers to assert the Superiority's authority in exchange for killing all the cytonics.

The delvers attack Spensa by inhabiting the minds of beings unable to resist their control and sending destroyed buildings through the Nowhere, but she manages to evade them and lead the pirates to Surehold, the superiority center for mining acclivity stone.

There, she and Chet view a memory of Jason Write, the first human to discover he was cytonic and learn that the secrets of the delvers can be found in the lightburst.

Sanderson has stated that he feels the novel is a "little bit of a diversion" from the main story set to focus specifically on Spensa's arc in the aftermath of Starsight's last chapter.

[5] Kirkus Reviews was critical of pacing caused by the increased focus on character development but praised the "wild aerial dogfights and larger battles", "terrific combat scenes" and "galleries of the multispecies cast members.

"[6] Sanderson and Janci Patterson released three tie-in audiobooks called Sunreach, ReDawn and Evershore based around characters on Detritus: FM, Alanik, and Jorgen.