The Dragonets of Destiny are on their way to see the NightWings - and Starflight doesn't need his psychic powers to know it isn't going to go well for him and the other dragonets.
Starflight knows it's his duty as a NightWing to convince the other dragonets to choose Blister as queen. But he can't help feeling that there's something Morrowseer and the other NightWings aren't telling him, something that could put his friends in grave danger. While other NightWings have their powers to help them, Starflight has to rely on his brain - and with SkyWings chasing them and Blister and Burn on their tails, that might not be enough.
PrologueThe prologue is about Reed and his siblings in a battle between the IceWings, which made Marsh freak out since he saw his sister Crane die in front of him during their first battle. After the battle is over, Umber claims to have noticed a scavenger den the IceWings were after. Reed takes note but does not ponder on it any more. He then thinks about joining the Talons of Peace with his siblings. The prologue ends with him not wanting to lose anyone else in the war, having already lost their sister Crane.
Part One: The Secret Plan
The book begins with Starflight worrying about where Sunny is. Starflight is awoken by his sister, Fierceteeth, who dumped salt water on him. He is introduced to all of the NightWing dragonets, however, the introduction is cut short when Morrowseer storms into the room, demanding that Starflight join him at the council. Starflight nervously comes along.
At the council, Starflight watches as the council debates attacking the RainWings. He witnesses Vengeance's death when he crashes the meeting, accusing Deathbringer of letting Glory escape. Greatness orders Deathbringer to be taken to the dungeon, and the meeting disbands.
Morrowseer takes Starflight to an island to hunt, and, after listening to Starflight rant on and on about the strange hunting habits of NightWings, confirms who his father is. Morrowseer takes Starflight to the labs, but on the way, they meet Fatespeaker. Morrowseer agrees to take her to the labs if she promises to be quiet, and she happily agrees. When they meet Mastermind, Morrowseer goes away, leaving them for a father-son bonding moment.
At first, when Starflight meets his father, Mastermind, he is filled with elation at the prospect of having such a smart father, but when he is given a tour by Mastermind around the labs, he is sickened by the fact that his father is abducting and torturing dragons without even caring. When Mastermind shows him a RainWing test subject - which turns out to be Orchid - Starflight says reassuring things to her, turning her a pink color. Mastermind marvels at this, wondering why and how she turned colors. When Starflight realizes that Fatespeaker is reading his mind, he momentarily panics, but then relaxes when Fatespeaker gives him a look that says, "We'll be talking about this later."Morrowseer then comes back, saying that Starflight must be introduced to the "others". However, Starflight is not paying attention, but instead pondering why the NightWings would be abducting the RainWings. He figures out their plan, and part one ends with him thinking, "I've figured out the NightWings' plan. But now, what do I do about it?"
Part Two: The Queen's Secret
Starflight is brought to meet the false dragonets, and almost immediately afterward, Morrowseer orders the dragonets to kill Starflight. He runs away and hides in the RainWing prisons, where Fatespeaker finds him and brings him back. The other False Dragonets fail in killing him and they all soon go to sleep.
Fatespeaker wakes Starflight to explore the volcano. They find the old treasury and Starflight discovers a dreamvisitor. He attempts to contact the real dragonets with it but enters Kinkajou's dreams and is unable to contact the others in their dreams. However, he successfully contacts Glory. He wakes and Morrowseer brings them to the main land, to try to convince the SkyWings to switch alliances to Blister. They fail and Morrowseer kills the SkyWings. Squid then says he doesn't want to do this any more and Morrowseer sends him away, saying he hopes Squid would die.
The next night Fatespeaker and Starflight wander off to meet the Queen. They meet her and find out she is forced to stay in a tub of lava because an IceWing shot it's breath into her throat. The lava and ice cancel each other out. If she left the lava, the ice breath would finish its work. Starflight returns to his bed and manages to contact Glory with the dreamvisitor and tells her about everything.
The next day Morrowseer instructs them to do battle training and while attempting to kill Fatespeaker, Viper falls into the lava, but manages to accidentally scratch Flame with her venomous tail. Morrowseer attempts to save Flame and leaves Viper for death. Starflight decides to escape with Fatespeaker and Flame to the rainforest. Flame becomes very ill.
Part Three: The Truth
Starflight tricks the guards into letting them into the rainforest. They decide to let them in. Immediately after they come in, RainWings pin them down, as ordered by Tsunami. Starflight and Tsunami spot each other and Tsunami explains a bit and brings them to Glory, Sunny and Clay. Fatespeaker demands who Sunny is, and soon after finds they're a lot alike. They plan how they're going to do the battle and decide they will go in within a few hours. Sunny suggests a new way of fighting for RainWings: Sleeping darts. Soon all the RainWings are armed with their sleeping darts. Starflight believes he might die in the fight, so he confesses to Sunny that he loves her. She says she loves him back but it is not known if she shares the same kind of affection as him. Starflight then goes into battle. Glory frees Orchid first and tells Liana and Grandeur how to free the RainWings with the spear. They then go to speak to Queen Battlewinner. As they are entering her chamber, Starflight notices the ground shaking, and realized the volcano is about to erupt. Glory demands that Battlewinner stops the battle but the NightWing refuses. Starflight comes up with the idea for letting the NightWings come to the rainforest, as long as they accept Glory as their queen. Queen Battlewinner attempts to attack them, but having jumped out of her lava bath, the ice freezes her insides and kills her in a matter of seconds. Then they free Splendor and Deathbringer and tell the NightWings their plan. Almost all the dragons enter the rainforest, except for Morrowseer. As they are about to leave, Morrowseer tells them the prophecy is false and made up and then, for a moment is silhouetted by a fireball, and then consumed by it. Starflight then feels the blast on his scales and feels a stab of pain through his eyes (he might possibly be blind). Clay brings him to the rainforest and Fatespeaker comes up to him, (he was unsure whether or not it was Fatespeaker or Sunny at first) and he was then jabbed in the neck by a sleeping dart and is knocked unconscious.
Blaze is with Glacier, telling her about the dragonets. Glacier confirms that she only is supporting Blaze for the land. Glacier allows Blaze to go inside and thinks to herself about killing the dragonets if they don't choose Blaze.
Blister is with Nautilus and Squid who was found by the mountains after Morrowseer left him to fend for himself. Both Nautilus and Blister are wondering about Morrowseer's disappearance and why he sent her to a scavenger den. She realizes that the dragonets may be the reason of his disappearance and vows to kill them.
Burn is outside of her stronghold, with her brother, Smolder. They are talking about their prisoner, Queen Scarlet. Burn then tells him about how much a bore Queen Ruby is, and how she won't enter battle while her kingdom is in turmoil. Burn then states she will destroy the prophecy by killing the dragonets.
- The Dark Secret is the only book where the dragonet featured on the cover is fully depicted on the front panel only, including the dragonet's (Starflight's) wings.
- The Dark Secret is one the two books where the dragonet is not in air (the other one being The Lost Heir).
- Starflight's scales appear to be brown in the picture because of the reflection of the lava.
- The Dark Secret is the only book where the dragonet's (Starflight's) scales aren't their true color. (With the exception of The Hidden Kingdom, whose featured dragonet can change her scale color.)
- On the cover of The Dark Secret, Starflight's tongue is red, because of the lava.
- Even though a typical NightWing's scales don't go up their wings, the dragonet on the cover does.
- Even though the guide shows NightWings with silver spots going down their neck, the cover doesn't include it.
- It was following the release of this book that Wings of Fire made the New York Times bestseller list.