Crater, a boy named Crater mines for precious dust on the moon. Crater is one of the weaker boys, so when he shows his bravery by saving another miner, he is selected to travel with a convoy to deliver the dust. Crater is attacked and separated from the convoy by crowhoppers. They are lethal assassins, and they are the most feared thing on the moon. Crater faces a warship, lots of crowhoppers, and a ton of trouble with the whole convoy.
This book shows the problems with too much advancement for the human race. It proves a point about energy consumption. That's why Crater is on the moon--to mine the dust for energy. This should prove a point to all who wish to keep using oil, and to anyone supporting them. I think that anyone should be able to read this book, but it has a lot of violence.