The fifth and final book in the first arc of the
Wings of Fire series is set in Pyrrhia, a continent inhabited by seven tribes of dragons locked in a twenty-year war. The conflict began when three SandWing sisters, Burn, Blister, and Blaze, fought over their mother Queen Oasis's throne after scavengers, small humanlike creatures dragons regard as prey, killed her. A prophecy foretold that five dragonets would end the war: Clay (a MudWing), Tsunami (a SeaWing), Glory (a RainWing), Starflight (a NightWing), and Sunny (a SandWing), raised by the Talons of Peace, a cross-tribe resistance movement. In the previous book, the NightWing Morrowseer revealed he fabricated the prophecy. This installment is narrated from Sunny's perspective.
A prologue set twenty years earlier shows Queen Oasis discovering that scavengers have raided her treasure rooms and stolen the Eye of Onyx, an artifact enchanted by an animus, a dragon born with innate magical powers. She flies out alone to pursue them, a fatally overconfident decision, while her daughter Blister turns toward the unlocked treasure rooms instead of fetching backup.
The main story opens as Sunny scrambles from a tunnel into the rainforest, devastated by the prophecy's falseness. She is a small, oddly colored SandWing with green eyes and no venomous tail barb, traits that have always made her feel like an outsider. While everyone tends to Clay, who emerges carrying a severely burned and unconscious Starflight, three NightWings drag Sunny into the forest: Fierceteeth (Starflight's half sister), Strongwings, and Preyhunter. They plan to sell her to one of the SandWing queens. The NightWings possess the Obsidian Mirror, an animus-enchanted artifact that lets them spy on any named dragon. Through it, Sunny overhears Tsunami dismiss her as always happy and certain to forget the prophecy within a week, confirming her deepest frustration that her friends see her as cheerful but trivial. Sunny escapes and resolves to follow the NightWings to prevent them from betraying the dragonets' location.
Over several days, Sunny tracks the NightWings westward and steals the Obsidian Mirror while they sleep. She uses it to spy on Blister and overhears the princess discuss a secret plan to kill Burn. Sunny buries the mirror in the sand near the Scorpion Den, a walled desert city, to keep it from the wrong hands.
In the Scorpion Den, a SandWing named Six-Claws brings Sunny before the Outclaws, the gang that controls the city. Their leader, Thorn, interrogates the captured NightWings; when Preyhunter attacks her, Thorn kills him. In a private meeting, Thorn reveals she has spent years searching for Sunny. Dune, one of the dragonets' guardians, did not find Sunny's egg abandoned as the dragonets were told; he stole it from Thorn's hiding place. Thorn declares, "You're my daughter" (73), and Sunny experiences the reunion she always dreamed of.
While Thorn handles a crisis involving a dragonbite viper, a deadly snake whose venom can kill dragons, and a fire in the city, a scarred Outclaw named Addax, a former soldier of Burn's army who hopes to use Sunny to regain his place there, kidnaps Sunny by threatening Six-Claws's young daughter. Sunny volunteers to go with Addax to protect the child. He delivers her to Burn's stronghold, where Burn's brother Smolder chains Sunny in the weirdling tower alongside Burn's collection of stuffed and deformed dragons. Also chained there is Queen Scarlet of the SkyWings, alive but disfigured, who threatens vengeance. Smolder's pet scavenger, Flower, one of the three who robbed Queen Oasis, stays with Sunny through the night.
Smolder shows Sunny the empty treasure rooms, and she deduces that the scavengers could not have carried so much: Someone else stole the bulk while the dragons pursued the scavengers. Smolder reveals the Eye of Onyx grants any SandWing who holds it the authority to rule, explaining why no sister has claimed legitimate queenship.
Thorn and the Outclaws attack the stronghold. Peril, a SkyWing whose scales burn hot enough to melt other dragons, arrives to free Queen Scarlet. Sunny tells Peril that her mother, Kestrel, is dead, then persuades Peril to stop the battle by appealing to their shared longing for mothers who wanted them. Peril's reputation causes the soldiers to surrender. Smolder produces an intercepted letter from a NightWing named Stonemover, asking Thorn to meet him at Jade Mountain. As Burn's forces approach, Sunny burns through a locked door and escapes with the Outclaws. Peril frees Scarlet, and the two fly north.
Thorn reveals that Stonemover is Sunny's father and an animus, making Sunny half NightWing, which explains her unusual appearance. Thorn tells Sunny never to let any dragon make her feel she should not exist. On Jade Mountain, Sunny finds Stonemover in a cave, his scales slowly turning to stone from a self-inflicted curse meant to contain his magic. He confirms the prophecy is fabricated. Sunny resolves to end the war anyway, because it needs ending regardless of prophecy.
That night, a scavenger holding a dreamvisitor, an animus-enchanted gem that lets its holder enter others' dreams, appears in Sunny's sleep. She tracks the creature to a burned scavenger village and recovers the dreamvisitor along with other treasure, but the Eye of Onyx is not among the items.
Sunny returns to the rainforest and reunites with her friends. Starflight's eyes are bandaged, and Fatespeaker, a NightWing dragonet raised as an alternate prophecy candidate, helps care for him. Sunny proposes that the dragonets assemble all three SandWing sisters and let the SandWings choose their own queen, firmly rejecting assassination or magic as solutions. Her friends are skeptical but agree. They split up: Sunny and Tsunami contact the Talons of Peace to reach Blister; Glory sends disguised RainWings to invite Blaze. In the Mud Kingdom, Sunny and Clay discover the MudWing army massed for a devastating offensive. Using the dreamvisitor, Sunny enters Queen Moorhen's nightmare and pleads with her to delay the invasion, then spends the night with Clay dreamvisiting soldiers to spread the message that the war is almost over.
On the appointed night, dragons from every tribe fill the stronghold. A mysterious comet has joined the three moons, creating a sky as bright as a brightest night, the rare celestial alignment tied to the prophecy. Burn, Blister, and Blaze each arrive believing the dragonets have chosen her. Sunny announces the sisters must decide peacefully who will be queen. All three refuse. Blister reveals she sent Burn a box supposedly containing a rare specimen for her collection. Burn opens it and lifts out a dragonbite viper, but a second viper hidden inside strikes her ankle, and she dies. The escaped viper races toward the dragonets; Clay knocks Sunny, Starflight, and Fatespeaker clear and is bitten. Peril arrives and burns the venom from Clay's wound with her fiery talons. Clay survives thanks to his fireproof scales, though the wound leaves him permanently scarred.
With Burn dead, Blister turns on Blaze. As the one-sided duel unfolds, Flower tugs Sunny toward Queen Oasis's grave. Sunny, Tsunami, Glory, and Thorn dig up the skeleton and find treasure Flower hid in the queen's mouth twenty years ago, including the Eye of Onyx, a black stone set in a necklace of gold dragon wings. Sunny holds the Eye and realizes she could claim the throne, but she decides she does not want to be queen; she wants to teach dragonets to make peace. She places the Eye in Thorn's talons, declaring her mother the new SandWing queen. Blister snatches the Eye, but the enchantment rejects her: Lightning rips through her body, destroying her. Blaze survives, and SandWings bow before Queen Thorn. The war is over.
One month later, the five dragonets stand on Jade Mountain, planning an inter-tribe school where dragonets from every kingdom can learn together. Sunny reflects on unresolved threats, including the vanished Queen Scarlet and the Obsidian Mirror she buried in the desert, but she is at peace. She privately acknowledges she loves Starflight as a brother, not romantically, and is glad he has Fatespeaker. The dragonets agree there will be no more prophecies. They spread their wings and leap together into the open sky.