In the future the UN has brought back an ancient way to keep the peace. The children of world leaders are held hostage - if a war begins, they pay with their lives.

Greta is the crown princess of the Panpolar Confederacy, a superpower formed of modern-day Canada. She is also a child of peace, a hostage held by the de facto ruler of the world: the great artificial intelligence, Talis. The hostages are Talis' strategy to keep the peace: If her country enters a war, Greta dies.

The system has worked for centuries. Parents don't want to see their children murdered.

Greta will be free if she can make it to her 18th birthday. Until then, she is prepared to die with dignity if necessary. But everything changes when Elian arrives at the prefecture. He's a hostage from a new American alliance, and he defies the machines that control every part of their lives - and is severely punished for it. Greta is furious that Elian has disrupted their quiet, structured world. But slowly his rebellion opens her eyes to the brutality of the rules they live under and to the subtle resistance of her companions. And Greta discovers her own quiet power.

Then Elian's country declares war on Greta's and invades the prefecture, taking the hostages hostage. Now the great Talis is furious and coming himself to mete out punishment - which surely means that Greta and Elian will be killed...unless Greta can think of a way to save them.