Bad news stuns the southern capital: a church plot has severed contact with the city of water, leaving Allen and Lydia stranded in the middle of enemy territory and a burgeoning civil war. And no aid can reach them while the impregnable Fortress of Seven Towers stands. To help their tutor, Allen's students will need to overcome the greatest defenses that nature and human ingenuity can create without him—and they'll need to work fast. Lynne Leinster, for one, doesn't know if she has it in her. Despite her tough talk, the young noblewoman feels intimidated by her friends' brilliance. What can she do that they can't do better? She'll need to find her answer soon, because this crisis will demand everything that the girls have to give. And all the while, a sinister conspiracy draws nearer to its goal.