Commander Tauri and his Orbiis team arrive at the Burav estate. They quickly confirm that the main well is contaminated with the guiding web fungus. Subsequent tests reveal that every person who lived and worked in the main house is infected, though Din and Princeps Seriv test negative. They deduce that Jalin Burav survived because he lived in separate quarters on the estate and therefore did not drink from the contaminated well.

Tauri and his team, while surveying the mansion’s stability to determine whether it was safe to enter, notice an architectural anomaly: a section of the first floor that appears to have no doors or windows. After further investigation, they discover a secret, heavily fortified vault built into the house’s foundation, which seems to have survived the blaze intact. The vault has a door with a combination lock. Above the door is an inscription in the Kurmini language, which Ana knows. She translates it as “Brilliance is forever fecund” (183), noting that she despises such riddles. The tumblers on the combination lock use the same Kurmini characters, and Ana begins the task of trying to break the code, though this is likely to take some time. 

On the carriage ride back to Lacanthim, Ana decodes the flashing lights Din saw in the forest. It was a repeated message in Legionnaire’s lantern code spelling the word “calm.” She concludes that there is a conspiracy at work: Someone was using the lights to communicate with an operative inside the Burav estate. She surmises that the operative failed to obey the instruction, “calm,” and rashly burned the estate down. Ana also deduces that the suspicious man seen by the kitchen maid was not the arsonist but an intended victim, lured to the scene to be either killed or framed. Based on the description, she correctly identifies the prowler as an Armenta and directs their carriage to the Crooked Horn, an inn favored by the family. There, they find Ippeas Armenta waiting to turn himself in.

At the custodi office, Ippeas Armenta explains that he was lured to the Burav estate by an anonymous letter, purportedly from a servant employed by the Burav family. The letter, which he was instructed to burn, claimed to offer evidence of Castus Armenta’s innocence and contained personal details about Ippeas and his betrothed, Fotia Kol, that only Castus would have known—passed on to the servant through Zansay. Ippeas explains that while he was hesitating near the mansion, he was spotted by a drunk valet who mistook him for Burilis Burav and mentioned Burilis’s frequent “forest jaunts” with a “lantern and smokes.” Afraid of being recognized, Ippeas started to flee, but when the fire erupted, he ran back to help. He rescued the kitchen maid from the smoke-filled kitchens, but when he turned back, the whole house was aflame, and there was nothing more he could do. Ana points out the irony that this same kitchen maid has now identified him as a potential murderer.

A test administered to Ippeas reveals that he is infected with the guiding web. Ana has him placed in a cell for his own protection, believing the killer will try to harm him again. She then instructs Din to rest in an adjacent cell, anticipating that his sister, Fotia, will soon arrive.

Fotia arrives at the jail enraged that Ippeas was foolish enough to believe the message that lured him to the Burav estate. She upbraids him for endangering himself and casting even greater suspicion on himself and the Armenta family. After her anger passes, she learns the full details of the investigation, including Ippeas’s infection. Din gives her a test as well, and all are relieved to learn that she is not infected. Fotia recalls Castus’s claim to have been followed by an unseen person as he fled into the forest after Zaynas’s death. She theorizes that this other person—presumably the killer—was not in fact following Castus but simply going in the same direction. Castus was trying to reach Gaddar’s Glade—a shrine where he hoped to pray for deliverance from his curse. Fotia notes that the location of Gaddar’s Glade also happens to be where the forest is thinnest. Anyone hoping to pass through the forest—and thus move unseen between the Burav and Armenta lands—would do so here. Over Ippeas’s objections, Fotia arranges to take Din to Gaddar’s Glade.

Fotia leads Din to the shrine, where Din notices the strange, almost inhuman appearance of the ancient Daljen hero Gaddar as depicted in the statue. An unconscious memory begins to surface, triggered by the statue. Din retrieves a coin from his pocket and notes a resemblance between the ancient Daljen figure and the emperor’s image on the coin. He then spots footprints in a section of the forest that should be inaccessible. One footprint is pointing toward the glade, the other away. Commander Tauri arrives and explains that the forest contains hidden paths, or “seams,” that can be opened using a special thurible that emits a reagent in the form of smoke. This information leads Din to recall what Ippeas told him: When the drunk valet at the Barav estate thought Ippeas was Burilis Barav, he mentioned Burilis’s habit of carrying a lantern and “smokes” into the forest. Din now surmises that these “smokes” were in fact a thurible like the one used by Tauri. Din and Tauri follow the seam and discover a hidden cache containing pipes designed to control the web, a vial of the fungus, and a music book with instructions on how to use the web to control people.

The music book found in the forest cache contains tunes for awakening and conditioning the guiding web. It also includes a final tune labeled “LYSIS,” which Tauri explains refers to the final breakdown or bursting of infected tissue, accompanied by the note “NOT IMMEDIATE.” A loose slip of parchment reveals a message written by a subordinate conspirator to the lead conspirator who had promised forgiveness, expressing a deep sense of betrayal and vowing revenge in the afterlife.

Ana notes that as an Orbiis officer, Burilis Barav controlled access to the altered forest. This, combined with the discovery of the secret paths, strengthens Ana’s theory that Burilis lied about the origin of the guiding web and that his hidden vault contains evidence of his deception. Commander Tauri then reveals the forest’s greatest secret: its center does not contain a tomb, but one of the Empire’s sealed “Touched Sites”—extremely dangerous places, often containing the bodies of dead leviathans or lethal contagions, to which access is highly restricted. He describes it as a massive, perfectly black stone plug of unknown origin sealing something mysterious deep within the earth. Ana speculates that this site is connected to the historical disappearance of the ancient Daljen tribe.

Ana tasks Fotia with secretly questioning the Armenta servants about the death of Sagma Armenta, since Sagma’s death (by hanging) was notably different from the deaths of her siblings. Ana and Tauri note that using the web to program a suicide by hanging would be difficult if not impossible, since hanging oneself is a complex action that can only be done once, while the web conditions its subjects through repetitive, simple tasks. As Trikao Armenta arrives at the inn, Ana warns Din and Fotia that her plan is dangerous and risks turning the whole town against them.

Din accompanies Fotia and a deeply distressed Trikao to the jail to visit Ippeas. On the way, they are accosted several times by angry townspeople, who believe the Armentas are responsible for the fire at the Burav estate. Trikao sends Fotia in ahead of him to visit Ippeas. While Din and Trikao wait outside, horrific screams erupt from the infirmary wing. Din rushes in and finds Seriv badly wounded, having been attacked when Castus grabbed a knife; Seriv gasps that Castus then pursued the fleeing medikker Evrik into the lading passage. Trikao agrees to carry the wounded Seriv to a medikker, while Din sends Fotia urgently to fetch Commander Tauri and the Orbiis. He instructs her to be on the lookout for anyone playing a pipe or acting suspicious, as he believes that someone must have played the “Lysis” tune from the music book to trigger Castus’s fruiting. 

Din enters the lading deck and finds that Castus Armenta has “fruited”: A massive fungal growth has erupted from the side of his head. Castus should be dead, but his body continues to function, attacking the medikker Evrik in a compulsive repetition of the slaughterhouse motions he was conditioned with. After a struggle, Din is forced to decapitate the undead Castus to end the attack. He emerges to find Fotia already returned with Tauri. She has not seen anyone lingering near the jail.

Din and Ana connect the eruption to the “LYSIS” tune from the killer’s music book. Because the tune’s effect is delayed, the killer could have played it nearby and escaped long before the horrific transformation began. Faced with this new horror and the threat to his son, Trikao Armenta gives Ana and Tauri permission to exhume the bodies of his niece and nephews—Lyimo, Sagma, and Gevma—for examination. Tauri reacts with unexplained unease upon learning the sepulcher’s location relative to the next day’s wind direction, then abruptly agrees to proceed without explaining his concern. Ana expresses frustration with Burav’s vault—she has made no progress in figuring out the combination. She notes that the numeral 1 on the lock’s tumblers is inscribed without serifs, unlike all the other numerals, which are inscribed in the Imperial Standard font. Later, Ana warns Din to be wary of Tauri, calling him “too important, and too clever.”