A Rib Cage

Enna's father is a general in the military of a future nation. Now, she and her three older siblings, twins Robin and Alva and fourteen-year old Willow must accompany him on a journey across the dessert to find a lost group of soldiers who were traveling across the wasteland to negotiate with another country. Locked inside "The Crawler" The four siblings encounter all kinds of new mysteries, but when the crawler is put in danger, will Enna and her siblings be able to save it and their father?
Written with "Willywonka1019", JMS, and EPS