Lummerland is extremely peaceful: An island in the middle of the ocean with two mountains. One day something unexpected happens: Jim Knopf arrives.

Jim Knopf, Lukas, Frau Waas, König Alfons, der Viertelvorzwölfte, and Emma, the locomotive, live on the island Lummerland. When Emma is supposed to leave the island because of lack of space for her, Lukas, Emma und Jim flee Lummerland. Thye arrive in China. There they find out that Li Si, the emperor's daughter, was kidnapped and taken to Drachenland and decide to rescue her.

Jim Knopf, Lukas and Emma want to rescue Li Si, the daughter of the emperor of China. On their journey to Drachenstadt they come across many strange places that need to be crossed.

On their way to Drachenstadt Lukas, Jim Knopf und Emma meet Nepomuk, who tells them how to get into Drachenstadt: They must dress Emma as dragon. From this point forward things are getting complicated. Will the rescue be possible?