The prologue unfolds in two movements. The first follows a young Wax in the Terris Village, where an evening of adolescent mischief leads him to uncover a genuine crime and kill a boy named Forch in self-defence, cementing his conviction that the Village is not his home. The second jumps forward to a constabulary raid with Wayne, establishing the seasoned lawman Wax has become, before he heads off to marry Steris.
Wax flies across Elendel to his wedding, savouring the joy of Allomantic flight, and finds Steris methodically prepared for every contingency. His lingering grief over Lessie and resentment toward Harmony surface as the ceremony begins. A water tower crashes through the church dome, ending the wedding before vows are exchanged and establishing the novel's pattern of plans undone by violence.
The aftermath of the collapsed wedding splits into two perspectives. Wax admits to Steris that he is relieved the ceremony was interrupted, a confession that wounds her even as she takes it in stride. Marasi discovers Wayne orchestrated a smaller disruption that was overtaken by the real sabotage, then meets VenDell, who recruits her after Wax refused the kandra's request.
VenDell lays out the novel's central quest in Wax's study. He explains the theoretical possibility of unkeyed metalminds and the mythical Bands of Mourning, presents photographs from a kandra expedition that went wrong, and reveals that Wax's sister Telsin is being held prisoner in New Seran. The chapter converts Wax's refusal into reluctant acceptance by making the mission personal.
The group prepares to depart for New Seran. Steris inserts herself into the expedition with characteristic pragmatism, VenDell declines fieldwork, and Wayne makes a final visit to Ranette to close that chapter of his life for good. The preparations establish each character's role and emotional baggage before the journey begins.
The train journey south reveals a world larger and more restless than Elendel acknowledges. Wax opens a package of experimental weapons from Ranette, witnesses anti-Elendel protests at a station, and discovers Steris researching intimacy with the same methodical rigour she brings to everything. The chapter widens the political landscape while deepening the quiet courtship between Wax and Steris.
Marasi studies VenDell's expedition notes aboard the train, finding references to red-skinned creatures and warnings about Hemalurgy from Spook's writings. Wayne drifts through the carriages collecting accents. When Marasi delivers a pouch containing an earring meant for Wax, she returns to find their train car has been decoupled and a gunman waiting for her.
A full-scale train robbery erupts across multiple viewpoints. Wax fights mounted bandits and a massive Coinshot who outclasses him physically, Steris reloads for Marasi during a firefight in the rear carriages, and a mysterious metal cube drains Wax's Allomantic reserves at a critical moment. Steris saves Wax by firing Ranette's oversized shotgun but is thrown from the train by the recoil.
Wax rescues Steris from the river using one of Ranette's devices, and she is exhilarated rather than shaken. Marasi encounters a calm man with a cane who drops a small metal cube before the train brakes hard. Wax dispatches the remaining bandits and the giant Coinshot, while Marasi traps the last group in a cadmium bubble. The chapter resolves the action set piece and plants the cube as a key artefact.
At the station, Wax learns the robbers belong to the Nightstreet Gang but suspects they are connected to something larger. He finds Wayne hidden below the luggage compartment with MeLaan, who missed the entire battle. Marasi produces the cube she recovered, and Wax decides to press on to New Seran despite the ambush. The chapter regroups the party and introduces the cube's significance.
The group arrives in New Seran and is struck by the terraced beauty of the city. Wax resists the pull of an old nemesis spotted in a broadsheet headline, choosing to stay focused on finding his uncle. At the hotel, Steris presents the staff with a detailed list of potential catastrophes, and the party splits: Marasi and Wayne to search graveyards for the missing spike, Wax and Steris to attend a political gathering.
The chapter interleaves a high-society party with a graveyard investigation. Wax and Steris arrive at Kelesina Shores's estate, where Steris's meticulous preparation proves invaluable. Wayne and Marasi bluff their way into a bank to trace cemetery corruption, discovering that every grave worker in New Seran is selling the personal effects of the dead. The parallel threads establish how the Set operates through both elite social networks and petty crime.
At the party, Wax examines a strange two-metal coin given to him by a beggar and encounters a woman named Khriss who quizzes him about combined Allomantic powers before vanishing. In the graveyard, Wayne and Marasi convince a corrupt gravedigger named Dechamp to exhume a body for them. The coin's unknown script and the mysterious scholar both point toward forces operating well beyond the Basin's borders.
Wax works an informant named Devlin Airs, who warns of a secret building project involving Allomancers and an approaching civil war. He then confronts Kelesina directly about the strange coins, rattling her enough that she flees the party. Steris enables Wax's pursuit by deliberately vomiting on the banquet table as a diversion. In the graveyard, Wayne pulls Marasi into a grave as gunfire erupts around them.
Wayne and Marasi survive a Set ambush in the cemetery through speed bubbles and improvised tactics. Wax prowls Kelesina's estate with Steris, who surprises him by producing a handgun she smuggled in strapped to her thigh. Marasi discovers a ledger in Dechamp's shack that reveals where the stolen spike was sent: a remote village called Dulsing.
Wayne and Marasi interrogate a middleman named Templeton Fig by having Marasi impersonate Death, extracting confirmation that the spike was forwarded to Dulsing. Wax infiltrates deeper into Kelesina's manor and overhears his uncle Edwarn speaking to her through some kind of device, discussing how to keep Wax distracted with side quests. When Wax bursts in, only the two women remain in the room with a mysterious box on the table.
Edwarn's voice projects from the box as Wax screams at him about Telsin. The Terris steward reveals herself as a Feruchemist, kills Kelesina, and frames Wax for the murder. MeLaan intervenes, defeating the steward with aluminium bones, and Wax recovers a gold metalmind bracelet from the body. He flees with Steris, and in the flight over the mists he kisses her for the first time. Back at the hotel, the group hastily departs as constables close in, and Wax decides to push on toward Dulsing rather than retreat to Elendel.
On the stagecoach ride through rough country, Marasi discovers a hidden switch on the metal cube. When she burns cadmium near it, the cube vibrates and amplifies her Allomancy. Wax experiments further and confirms the cube extends Allomantic abilities. He gives it to Marasi, whose time-slowing power benefits most from the amplification, and passes the gold metalmind to Wayne, who marvels at an unkeyed Bloodmaker reserve anyone can use.
The group reaches the Set's facility near Dulsing and finds a massive building under construction guarding a damaged ship unlike anything they have seen. They split into two teams: Marasi and MeLaan search for the spike, while Wax and Wayne hunt for Edwarn. Wayne's infiltration via the Spoiled Tomato plan and a series of bluffs gets them inside, where the scale of the Set's operation becomes clear.
Marasi and MeLaan explore the ship's interior and break into Irich's quarters, recovering both the spike and a second cube. Meanwhile, Wax spots Telsin being held in a separate room and Wayne bluffs his way in using an engineer disguise. Marasi opens a locked door and discovers caged prisoners wearing strange masks, one of whom extends a human hand and says please. Wax reunites with Telsin, who immediately shoots her Coinshot guard with the gun he gives her.