While Henry, Jessie, Violet, and Benny were eating lunch, Benny fell into a sinkhole. So everyone got in and saw that Benny wasn't too far down. They went just a little farther down in the cave and saw it was okay. So they got out and got their supplies, and went to tell Mr. Howe that they were going into a cave. So they went in and Benny saw monster tracks half way down. Then they saw a tunnel and went into the tunnel. They saw a man that did not say anything to them, and Benny called him Joe Caveman. I like the end when Benny finds a Rockville diamond. They get to take it home. How Benny found the diamond was it was in the right place to make a rainbow.