Tom and Jun encounter unexpected dangers and are separated while exploring the Hidden Realm of dragons. Tom introduces Jun to the dragon world, and Jun bonds with a dragon of her own – Wu and Wei.
Tom and the others debate how to keep the dragons a secret, even as a rambunctious young “cloaking” dragon gets loose in town and pursues a friendship with a Alex.
Tom has to keep his mom, Olivia, distracted while Jun, Alex, and D’Angelo use a new dragon to close off a cave leading to the Crystal Realm, and prevent her from discovering the dragons.
Tom and the riders go in search of Thunder and must face a gauntlet of dangerous dragons to find their lost friend. Along the way, Tom reveals his big secret to D’Angelo and Alex.
Alex and Eugene find themselves at odds with Tom and their fellow dragon riders when Feathers and Webmaster go missing during a blizzard in the Ice Realm.
Jun struggles to convince Tom to trust her faith in myths over the Book of Dragons when they venture to a place that his book seems to say is extremely dangerous.
When 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.