At Gelfar, Giren Malonan orders Dyrnick Vosh to return to New Norn, but the adventurers defend their guide and persuade the ranger to let the expedition continue. Giren leaves Dyrnick a magical handaxe and reveals that the barbarian carries a scroll of Revivify before departing. The party repairs an abandoned boat, fits the white-crystal lantern into a pedestal on the shore, and awakens an ethereal bridge across the Black Channel. Removing the lantern limits the visible bridge to the light surrounding its bearer, forcing the company to advance together while towing the boat. An immense Varian serpent attacks midway across, nearly swallowing Olive and hurling travelers toward the sea, but the party remembers the carving at the Fangled Bridge and sings the Song of Tyve. The music calms the beast, which releases Olive and disappears beneath the waves. On the Bleakmire, Dyrnick finally confesses that the shaman's vision, the awakening Dreg'Damor, and the ensorcelled winter were inventions. His daughter Dahlia suffers from the walking rot, and he believes a pale chalice left by people who mastered life and death may cure her. Although angered by the deception, the adventurers continue because their shared nightmares and the danger at the keep remain real.
Inside the Ebon Keep, every exit seals and the fortress begins draining the visitors' shadows, leaving them only hours to escape. The shadowless spirit of Kilcary Zorn Kragthos, husband of Isha Delgar and father of Entos, greets them with riddles and fragmented warnings about Vindelgar's madness, Tasha's sacrifice, a prism, a chalice, and poison hidden in the greenhouse. The party battles coral wolds and shadowless inhabitants, recovers the poison, survives a ballroom filled with spectral dancers, and searches the nursery, bedchambers, docks, armory, laboratory, and prison. Tasha's shade reveals that Vindelgar stabbed her after she emptied the chalice in the prism chamber, while his plans show that the Tangled One's song convinced him he could extract darkness from mortal souls and produce a light powerful enough to humble Gavra. A shadowless captain admits the truth: the Tangled One turned their stolen shadows into a lighthouse meant to draw something from the depths. In the prism chamber, Dyrnick reaches the pale chalice and triggers the machinery. Thousands of stolen shadows pour into it, black ichor raises Vindelgar and his shadowless defenders, and the party defeats them beneath unpredictable beams from the crystal prism. When the darkness returns to the chalice, Dyrnick opens it and finds no cure for Dahlia. The lantern then reveals a secret staircase behind the throne.
The staircase descends into the Tangled Depths, where five more chalices surround a sealed sarcophagus with an indentation matching the lantern. Placing the lantern in the seal shatters the chalices and consumes their darkness, causing the Tangled One to appear and reveal that her song guided the party to feed the ritual. She vanishes as a massive Depthcrawler emerges to defend the chamber. The greenhouse poison strips away the creature's supernatural defenses, but its freezing assault kills Olive outright. Dyrnick sacrifices the Revivify scroll he intended to preserve for himself and restores her to life. The wounded party endures the Depthcrawler's claws, cold, and parasitic brood until Olive lands the final divine strike. The Tangled One screams as cracks spread through the chamber, but the lantern's light seals them before the sarcophagus breaks away and falls into the ocean. Isha and Entos awaken as if surfacing from drowning, the shadowless dead find peace, and warmth returns to the Ebon Keep. Dyrnick leaves without the cure he sought, yet his lie has led to the rescue of the people trapped by the chalices and given Dahlia new allies. The survivors may return to New Norn, sail aboard the Gavran ship, pass through the newly revealed portal toward the mainland, or remain with Isha to restore Gelfar and the keep.
