Sky's End

The novel is set in the Skylands, a world of floating islands where society is governed by Meritocracy: a rigid caste system of Highs, Middles, and Lows determined by dueling and strength. Sixteen-year-old Conrad, once heir to the powerful Urwin family, lives in poverty with his dying mother, Elise, in an attic above a tavern on Holmstead Island. Six years earlier, his uncle, Ulrich of Urwin, murdered Conrad's father, seized the title of Archduke, exiled Conrad and Elise to the Lows, and took Conrad's younger sister, Ella, to raise in Urwin Manor.

Elise has lung rot from the acid clouds that drift into Low neighborhoods. After a severe convulsion, Conrad resolves to retrieve Ella to give his mother a reason to fight. He infiltrates Uncle's manor during a party but finds Ella's room empty. Guards capture him, and Uncle proposes a deal: If Conrad enters the Selection, the process by which the Twelve Trades choose recruits, Uncle will restore the Urwin name and reunite him with Ella. Conrad refuses and attacks Uncle. A guard drags him to the docks, but a devastating attack by gorgantauns, massive steel-scaled sky beasts, interrupts. The Lows suffer the worst destruction. A University student named Bryce of Damon saves Conrad from a collapsing wall. He races back to find the tavern destroyed and his mother dead.

McGill, the tavern owner, delivers a box Elise left behind: her white dueling cane and 12 golden coins she had hidden. Conrad holds a sky funeral, adopts the name Conrad of Elise, and uses the inheritance to rebuild his strength before accepting Uncle's Selection offer.

At the Selection ceremony, Master Koko of Ito, the elderly head of the Hunter Trade, selects four recruits: Sebastian of Abel, a small, unassuming boy; Bryce; Conrad; and Pound of Atwood, Conrad's rival whose family was recently cast down to Low after losing a duel Uncle engineered.

Conrad travels to Venator, Hunter's home island, for training at the Academy. His roommate, Roderick of Madison, a good-natured boy with exceptional marksmanship, persistently tries to befriend him. Master Koko confronts Conrad, calling him her weakest Selection despite his top marks because he refuses to build alliances. Heeding her warning, Conrad opens up, accepting Roderick's friendship and reconnecting with Bryce, who reveals she needs to win a ship to feed her starving people. Conrad promises to help her become Captain, knowing he cannot keep the promise.

A dueling tournament determines the first 16 Captains for the Gauntlet, Hunter's two-month gorgantaun-hunting competition. Before Conrad's second match, Pound ambushes him and breaks his rib. Conrad fights through the injury but narrowly loses to Bryce. Pound wins the tournament and drafts Conrad as Swabbie, the lowest rank on a ship.

The crew boards the Gladian, a Predator-class vessel assigned for the Gauntlet. Pound orders a reckless attack on a gorgantaun pod, and the Strategist, Patience, Sebastian's girlfriend, is killed when a gorgantaun's tail slices through the deck. Sebastian blames Conrad for Patience's death. Conrad secretly builds metallic wings from a lifeboat's sail, planning to take down a gorgantaun solo, the only way for a Swabbie to become Captain.

When a failed hunt leaves the Mechanic, Keeton of Jonson, falling through open sky, Conrad dives from the ship and catches her, saving her life. She pledges a life debt to him. Once the mandatory mutiny-free period expires, Pound resigns out of guilt for nearly getting Keeton killed. Sebastian, backed by Bryce and Eldon of Bartemius, the ship's Navigator, takes the captaincy. He proves far more dangerous than Pound, attempting to murder Conrad by sabotaging his safety belt during a hunt.

In a desperate battle with a class-five gorgantaun bull, the Gladian is critically damaged and Sebastian falls from the ship into the beast's mouth. Conrad activates his wings, dives off the stern, and lands on the gorgantaun's back. He runs the length of the creature, rips out its eye, and stuffs a homemade explosive into the socket, killing it. The crew votes him Captain unanimously.

Conrad consolidates leadership by assigning positions through democratic crew votes, an almost unprecedented practice, and takes the Swabbie duties himself to cement loyalty. Sebastian, who survived inside the gorgantaun's throat for 36 hours, is returned to the ship. Conrad stabs himself with Sebastian's knife and frames Sebastian for the attack, then confines him to the brig.

Keeton and Pound develop a plan to lure an entire gorgantaun pod into abandoned mining tunnels and collapse them. The hunt succeeds, and the Gladian surges to first place on the leaderboard. The competition with the rival ship Calamus intensifies as the Gauntlet nears its end.

Master Koko warns Conrad that spies from an unknown enemy have infiltrated all Twelve Trades. Conrad discovers Bryce communicating on a strange device with a figure she calls "Commander," who says a plan called "Downfall" will proceed and millions will die. Confronted, Bryce reveals she is from the Below, a civilization living beneath the black clouds on barren, sunless land. The gorgantauns were created by the Below as weapons against the Skylands. Bryce was sent as an infiltrator to pursue a peaceful solution, but her people have abandoned diplomacy for war. She drugs Conrad and escapes.

With the Gauntlet ending prematurely due to the infiltration crisis, the crew makes a final hunt against an ancient gorgantaun bull of unprecedented size. When the engine is destroyed mid-battle, Eldon steers the ship into the beast's throat, and the Gladian spears through its heart. The crew wins the Gauntlet with seconds to spare.

Master Koko takes the crew to Ironside, the Skylands' capital, where Conrad discovers Uncle has killed King Ferdinand in a duel and claimed the throne. Uncle shows Conrad ancient recordings of the Ascension, when cities rose into the sky to escape the Below's armies and the black clouds were created as a barrier. He offers Conrad the title of Prince and heir, promising to reunite him with Ella. Recognizing the threat of war and the need for stability, Conrad accepts despite his hatred of Uncle.

After her escape, Bryce is captured by Order, one of the Twelve Trades, and imprisoned beneath the King's Tower. She tells Conrad that Admiral Goerner, the Master of Order, is himself a Below infiltrator. Goerner seizes Uncle and Conrad, but the Gladian crew and a Hunter fleet led by Master Koko rescue them. Goerner opens a vortex in the black clouds, and through it rises the gigataun, a gorgantaun of incomprehensible size, perhaps a mile long. The beast ignores every attack, burrows into Ironside, and consumes the crystal heart keeping the island afloat. Ironside falls, killing thousands.

Uncle formally introduces Conrad as Prince before the assembled Masters. Conrad declines the offer of a massive carrier, choosing to remain on the Gladian. He retrieves 12-year-old Ella from the same jungle island he once survived as a child. She is fierce and marked by Uncle's influence but accepts their mother's white cane. Before the crew returns to Venator for the Hunter draft, Eldon says farewell to Conrad. Pound, who had earlier resigned, reverses his decision after learning his family rose to High without him. Conrad, Bryce, Roderick, Keeton, Pound, and Ella walk into the Academy together, preparing to draft new crewmembers and face the coming war against the Below.