After three generations, life on the Martian frontier is still raw and marginal. Jefferson Brodie believes extending the maglev rails south to the polar cap would alleviate most of the hardships by bringing needed water and ice to the settlers. Life gets complicated when a nosy reporter from Earth shows up along with the Regional Planetary Environment Control breathing down his neck to halt the rail construction, threatening not only Brodie's dream, but the settlers' very survival.