The parents leave for the night and tell the Riders not to bring the dragons to the surface while they're gone; D'Angelo and Eugene get locked in the hangar with the dragons after Eugene triggers a security lockdown.
Set 1,300 years after the events of How To Train Your Dragon, dragons are now just a legend to the modern world. When a geological anomaly opens up an immense, miles-deep fissure in the Earth's surface, scientists from all over the world gather at a new research facility to study the mysterious phenomenon. Soon a group of misfit kids, brought to the site by their parents, uncover the truth about dragons and where they've been hiding - a secret they must keep to themselves to protect what they've discovered.
Dragons: The Nine Realms - Break in Case of Emergency Synopsis and Schedule