The magic tree house takes Jack and Annie back in time to feudal Japan where the siblings learn about the ways of the Ninja.

Kai, a member of Sensei Wu's team of ninja warriors, helps Zane try to find answers about the past and finds himself in danger.

Cole, a member of Sensei Wu's team of ninja warriors, must keep his fellow ninjas' egos in check as he strives to unite the warriors and lead them on their dangerous missions.

Kai's sister, Nya, is kidnapped and he must learn Spinjitzu from Sensei Wu, a mysterious old man, to rescue her.

Sensei Wu must teach the Ninjago warriors the ancient art of spinjitzu in order to defeat Lord Garmadon, but first the ninja Jay, whose sense of humor is strong even in battle, must learn when it is the right time to be serious.

"Jay, Cole, Zane, Kai, and Sensei Wu are strangers in an even stranger land-- Garmadon City! But the name is not what's strange! The fact that everything is made of stone-- the streets, the buildings, the trees, even the people!-- that's the really strange part. But how do you save people who have been turned into stone who don't want to be saved, and will do anything to stop you?"--P. [4] of cover.

When the Overlord returns, transforming into the powerful Golden Master, it's up to ninja Cole, Jay, Kai, Zane, and Lloyd to defeat him.

"Late at night, when all is quiet and everyone is asleep, a ninja creeps silently through the house in search of treasure."--

"Michelangelo discovers an amazing creature in the sewer. Is it a friend, an enemy, or a monster?"--Page [4] of cover.

"Sensei Wu has sent Cole, Jay, Kai, and Zane on their first mission. The four Ninjago warriors must recover the Scythe of Quakes, one of the Four Golden Weapons, before they can go head-to-head with Lord Garmadon. But Kai has his own ideas about how to recover the Weapon. Can Cole, Jay, and Zane convince him they're all playing for the same team?"--Page 4 of cover.