Terpichore Murray is growing up on Mars. She wants to quit school and become an eco-prospector like her father. He has other ideas; not only does he want her to stay in school, he wants her along on his next long trip conducting a group of younger kids from the highlands at Mars's equator back to school in Wells City.

Early in the trip, disaster strikes-and it's up to Terry, without adult help, to get the survivors to safety, through several hundred miles of Martian wilderness. In the process, she will encounter the self-engineered "Mars-form" humans, usually shunned by the regular colonists-and One True, the collective intelligence that dominates Earth and from whom the Mars colonists are all separated. In the process she may well come of age and change the course of human history in the solar system... if Mars doesn't kill her first.