The Dark Secret (book)
The Dark Secret is the 4th book in the Wings of Fire series and features Starflight, the NightWing Dragonet of the Prophecy, as the main protagonist. It follows The Hidden Kingdom and preceedes The Brightest Night.
Summary
The Wings of Fire saga continues with a visit to the mysterious land of the NightWings, where Starflight must face a terrible choice - his home, or his friends?
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.
Starflight later finds out that during a sparing match, the false sandwing dragonet of prophecy gets pushed into the lava and Morrowseer plans on kidnapping Sunny! Starflight later on finds a dreamstone in which he uses to warn Tsunami about what might happen to Sunny.
Trivia
The Dark Secret is the second book where the dragonet featured on the cover is fully depicted on the front panel only, including the dragonet's wings.