This book tells the story of Mao Mao, Ali, Mu Jun and Archie's cave exploration. At first, they went to Deer Cave, but Mao Mao went the wrong way. Then, they fell into the underground cave. The cave is dark and dense, like a haunted house. Although it is terrible, there are some treasures that can't be seen on the ground, such as diamonds, stone flowers and goose tubes ... There are thousands of bats living in the cave, and their excrement weighs several tons every day! Then, they entered the rockfall area. Mao Mao and Jun Mu got into a corner of the cave, and A Zhi and Ali ran in, but just as they ran there, a very big stone fell from the ceiling, separating A Zhi from Mao Mao. They were sad, but they did not give up. Finally, Mao Mao found the "dog hole". Get into the hole like a "puppy" and follow the dog hole. They climbed onto A Zhi and Ali.

In the cave, they met many difficulties: there was no food; A Zhi has claustrophobia; Ali is in poor health ... but they have solved all the difficulties. Mu Jun is the oldest person in this book. He almost died trying to protect Mao Mao.

This book tells us how important it is to have the courage to overcome difficulties as a team member. This book also allows us to learn adventure knowledge that is not available in books. It's killing two birds with one stone. I never forget it.