A year after the 16 mysterious realms of Ninjago merge, Arin explores the Crossroads with his friend Sora and enters a race. They witness a dragon named Riyu being hunted by Rapton and a clash with the Dragon Hunters.

Lloyd frees Arin and Sora from the prison train and they escape with young dragon Riyu, who gives them a clue to find his home.

Lloyd trains Arin and Sora by impersonating Master Wu, but his lessons won't stick, so Sora and Arin sneak out of the Monastery to go to the Crossroads Carnival and rescue Lobbo from Kreel.

When the original Bounty crashes into the Monastery with no pilot, clues inside lead Lloyd, Arin, Sora and Riyu to Kai's last location - the former Realm of Madness - and they find Mud Creatures attacking two dragons.

When a MergeQuake unleashes a monster on the Cloud Kingdom, the Ninjas - who are passing by on the Bounty - defend the floating city.

When the Ninja meet their match in a Photac -- an indestructible techno-beast -- Sora believes that a mission to Imperium is the only way to destroy it.