Rue remembers two fragments of his forgotten Veyan life: a peaceful home beneath purple twilight with someone he loves, and a final assault upon Kypheron's volcanic lair. Valence Avorinth calls Rue his son and leads the Vey into the War of Fangs, hurling a sun-bright spear at the dragon god before the memory burns away around the image of a child Rue urges to run. In the present, Selendra Cassiandros offers the companions a skiff if several respected Gavrans will vouch for them and one will join their expedition, while Silas watches them leave. A disguised scribe slips Whisper a message directing the group to Gavra's clock tower, where Brill and Kyle reveal a hidden branch of the Arcanium. Kaphthalda explains that the order studies light, darkness, medicine, and the metaphysics of reality, while Brill says the Light Bender has called the companions by name and wants them to travel east. When they return to the Blooming Petal, they discover that unknown assailants have beaten Ernan and taken George Felrick. Zandra agrees to wait with the Dread Stalkers while Ernan, Brill, and the companions leave the city together.

During the overnight journey through Gavra, a black-armored figure follows the group until Lendo Malorian destroys it and vanishes back into the streets. At the Raggedy Rat, the companions meet Piccolo, a rare worker released after eight years in the Shattered Isles. He confirms that Yore and Gander's black-glint barrels came from a mine closed after a deadly calamity and were carried back aboard the Sarcoffner. Clot, another survivor from the Isles, then arrives badly wounded and infected by the black glint he carries. Th'Marck warns that the stone is dangerous, while Brill gives Clot an Arcanium antitoxin called the Juice that slows the spreading corruption. Clot takes the glint and a sealed message to an Arcanium safe house for further study. When morning comes, Rue awakens speaking the name Alokia and knows that he must find the person attached to it. Brill's ring grants the travelers passage through Gavra's eastern gate, and the group crosses the Triune Mountains through Velkommen, where its residents provide Vinterweed and Fire Root before the climb.

Inside the hidden Caverns of Shadow, Rue glimpses the temple in its ancient glory before Phineas Moon, the Light Bender, welcomes the companions beside his Panthex. Phineas gives Th'Marck the Eye of the Panthex, reveals Sethis as the forgotten goddess of twilight behind the present worship of Eth, and joins his Crystallic fragment to the piece from Rue's box. The restored portion opens a stair beneath Sethis's statue. Phineas warns that Tyve's glints are fading, the Dio Ostium is guarded by the Cult of the Iron Chain, and the mainland holds many dangerous paths, including Dragdah, Keph, Slyphus, the Houses of Tyve, and the source of the black rocks. He explains that the Plague makes the darkness within a soul manifest and tells the companions to remain in the light. Beneath the temple, Rue approaches a threefold tree of silver, living wood, and dripping gold, witnesses a Veyan woman consumed by light, and hears a command to remember his name as the vision isolates him in darkness. Elsewhere, the episode reveals that someone survived the shattering of an Ordos mirror three years earlier, while a hooded traveler and a small green goblin recover another Crystallic fragment beyond a black desert.