Dr. Alec Lupine is studying in Alabaster when he receives the call. A summons from Hyuginsha brings him to the sky-tower, where Doel’s flying treeship rests at the dock, but without any sign of Doel.
The Pridefolk first mate Rask speaks for the ship, first introducing the Atropos Loxos. He then explains that the captain, Gemma Fleetwind and the visiting Exemplar Gregory Gronstine were all last seen on the other side of a closing portal to the Underworld. Hyuginsha uses her “unlock thoughts” ability to send out a call to a necromantic diviner. Shortly thereafter, the astral form of the Tiger General Koscheva Deathqueller appears. Koscheva says that her spells place the stranded Doel and Fleetwind in a place called the “Shivered Drift.” Rask immediately prepares the ship.
Elsewhere and elsewhen, Valakar and Gemma plummet free from the unraveling Pandaemonic vessel. They came crashing down through sails of all things, landing on the deck of a strange patchwork ship, seemingly built from wrecks and flotsam. A rather irritated Spinner woman, a carpenter named Scaff, takes them to task for the damage. She explains that the small band of Underworld castaways has been attempting to get their airship working and escape to the living world for some time. Valakar takes to the air, and gets his first view of the Shivered Drift — a vast strand of shipwrecks, at the edge of a lightless sea, enough to perhaps be every lost ship since the dawn of sail.
In the living world, Doel’s crew carry Lupine, Rahatesh and Loxos to the city of Ghost. There they meet with Thane Tyrshade, who assists as best he can. He takes them to a small broken rowboat marooned at the edge of a city pond, overgrown with reeds and rotting away. There he reaches his maimed hand into the Underworld, and opens a portal. Lupine takes the precaution of shifting into his wolf form before he and Rahatesh step through. They see the Shivered Drift stretch out before them — and oddly enough, a small tent settlement, a mortal trade-town in a strange place.
The Underworld bazaar is a mishmash of tattered tents scraped together from broken spars and old sails. Various vendors and salvagers call out to Lupine, but he ignores them, heading instead for the apparent local boss. Boss Juko, a burly oni with a three-headed skeletal hound at his side, is at the center of the liveliest trade. As Lupine introduces himself and Rahatesh, he notes that a small group of Coleoths is selling fresh scrap from a Pandaemonic warship. He negotiates for the Coleoths to lead them to the wreck. Although initially hesitant, their speaker Skritter finds himself leading the way.
Back at the salvage ship, Valakar looks over the works and notices that it’s lacking a proper impulse engine. He takes to the air and spots a plume of smoke, likely the site of Exhumer-General Rezrael’s crash. Borrowing tools from Scaff, he and Gemma set out to pull an impulse engine from the Pandaemonic wreck.
Lupine and Rahatesh are the first to reach one of the crash sites. One of the Pandaemonic ship’s massive outriggers lies in a crater, still largely untouched. Lupine climbs up one of the many masts to get a higher viewpoint. He notes that a number of unnerving figureheads are scattered around the area, then notices people approaching at with great speed.
Then the figureheads move. They stretch out wings made of spars and tattered sail, take to the air, and begin to sing.
Valakar and Gemma arrive just as the fight breaks out. The shiver-sirens dive and swoop around the battlefield, strafing with killing songs. Gemma leaps into the air, kicking one after the other. Lupine moves to rip out the mast of one of the ships. The makeshift weapon proves more unwieldy than he can properly manage, though, and he abandons it. Rahatesh blocks one of the sonic wails, then retaliates with his shield. Valakar has the worst time of it initially, missing with his first shots and then being grappled by one of the strange things.
Lupine careens around the battlefield, one leap after the other, smashing through aged ships as he goes. Gemma begins to get a feel for the unearthly foes, and kicks one through the hold of one wreck. Rahatesh drops another with a well-placed strike, and Dr. Lupine finally brings one low with an aerial martial strike. Doel drops the final siren with a well-placed thunderbolt. Reunited, the Tiger Generals catch up as Valakar extracts the engine. Then Lupine tucks it under his arm, and they head back for the castaways’ ship.
Scaff is uncharacteristically impressed. She and Doel begin installing the engine, rigging it to make the ship airborne as best they can. Lupine excuses himself for a few minutes to return to the salvage-town on the Drift’s border. There he tenders his thanks to Boss Juko for the information. In return, the salvage-boss warns him that it seems that Scylla Morituri is wakening.
Dr. Lupine lopes back to the ship, as they’re preparing for takeoff. Along the way, he hears a faint song arising. He yells to the others, and Gemma takes to the rigging as Valakar readies the ship for launch. Gemma sees a luminescent form out among the wrecks, small but drawing nearer. As it moves, the broken ships start to move around it, becoming a rough skeleton of increasingly tremendous size.
The ship tears loose, and Doel takes the wheel. The oncoming assemblage of wrecks in woman’s form stretches out an immense hand to reach for them, and Doel is barely able to pull the ship beyond her grasp. The singing follows them as they set course out over the Underworld sea. They spy the rift out, a sliver of blue in the dark ceiling. The makeshift airship manages to outpace the jetsam colossus, leaving her wading in the lightless ocean after them.
They make it through the rift, into blue sunlit skies and green land spilling out beneath them. The rickety ship orients itself, and makes for the largest settlement in sight — one with principally red heraldry. The Tiger Generals realize they’re a continent away from home, in Cinnabria: the Blazing Phoenix Empire.