Crescent is a crowhopper-a genetically modified mercenary programmed for ruthless warfare. When she's taken prisoner by Crater Trueblood instead of being killed in battle, she thinks it's a disaster. Crater is weary of was. He's a miner, not a soldier. He'd rather be mining Helium-3 than battling the infernal crowhoppers. But after he captures Crescent and brings her to Moontown, he's surprised how much he enjoys her company. When she's falsely accused of murder, he becomes an outlaw to help her escape. The unlikely pair escapes into the "big suck" and wind up trekking with a caravan of mining pioneers toward a lunar ghost town called Endless Dust. To survive, they must do more than navigate the beautiful, desolate moonscape and battle a persistent band of crowhoppers sent to capture or kill them. They must decide what-and who-is truly worth fighting for.
In the beginning of Crescent, Crater and people everywhere on the moon have been at war for more than three years with Legionaries (Crow hoppers) which are designed and trained to kill. Their motto is "Life is death. Death is life."
In Part 1: Crater's Creature, Crater captured a crow hopper that was a woman. He named it Crescent. She is very strong and thinks that being captured by Crater is a disaster. Throughout the story, Crescent gets into a lot of trouble since she is a "monster" designed to kill.
Crater, Crescent, and the granddaughter of the Colonel named Maria Medaris and a few others finally made it to somewhere called Endless Dust.
When Crater said to Maria that they should get married, he found out that Crescent would die at the age of 21. He made a promise to Crescent that he would stay with her until she dies. Then there was a ship coming towards them and was driven by Crater's brother Petro. He said that Maria was needed over at Medaris company. Maria begged to Crater to come with her. But Crater made a promise to stay with Crescent until the last breath of her life. And with that, Crater stayed at Endless Dust with Crescent without watching Maria leave.