The morning after their return to the permanent fortress, Nila’s customized education began. The bitter scent of stale ink and the scratch of heavy parchment made her nervous but she knew if she were to lead then she must learn.

The low walnut table in the solar had been cleared of Ana's sweet-breads, replaced by massive, rolling topographical maps of the northern ridges and the southern valley. Iris stood on one side of the desk, a heavy brass pointer in her hand.

"We start with geography, Nila," Iris said, tapping the brass pointer against a thick, jagged ink line that snaked across the center of the largest parchment. "Because if...