In a world where everyone must be Marked in order to gain citizenship and participate in society, a group of youngsters who questions the system struggles to identify the true enemy--while pursuing a group of Markless teenagers.

After the events of the Fourth Trial, Martial soldiers hunt the two fugitives as they flee the city of Serra and undertake a perilous journey through the heart of the Empire. Laia is determined to break into Kauf - the Empire's most secure and dangerous prison - to save her brother, who is the key to the Scholars' survival. And Elias is determined to help Laia succeed, even if it means giving up his last chance at freedom. But dark forces, human and...

In a dark future, when North America has split into two warring nations, fifteen-year-olds Day, a famous criminal, and prodigy June, the brilliant soldier hired to capture him, discover that they have a common enemy.