Jeanna’s chest tightened thinking about leaving her warm secure cabin on the river barge to set off into a land of ice and danger.

Back in Kaldura, her life was built for the hot, coastal landscape. Homes were open and airy to let the breeze in, a single story on stilts, and cooking domes outside to keep the heat away from our beds. Kaldura was paradise.

But even mild Kaldurian winters could be...