Jack and Annie went to the old Japan. They found a  note where saying  a mission to save  Morgan. She was under a bad spell. They needed to find 4 things. They met two ninjas when they arrived in Japan. The ninjas led them to the master of ninjas. The master gave wanted to go back to the tree house on their own. That meant that they had to cross the cold river by themselves. The master wanted to test them which they were worthy to get the master's help. Jack and Annie struggled to cross the river even though it was the coldest that Jack had felt. One time they should have to pretend to be as quiet  and still as a rock. Because a Samuri who had no mercy, just cut down their enemies. Thankfully they escaped from the Samurai becuase of using and being nature. When they got the the tree house, the master of ninjas gave them a moonstone. After that they got back to Frog Creek,  Pennsylvania.