Legend (Legend, #1)

Once unknown as the western coast of United States, the Republic is now a nation perpetually at war with its neighbors, the Colonies.
Born into an elite family in one of the Republic's wealthiest districts, fifteen-year-old June is a military prodigy. Obedient, passionate, and committed to her country, she is being groomed for success in the Republic's highest circles.
Born into the slums of the Republic's Lake Sector, fifteen-year-old Day is the country's most wanted criminal. But his motives may not be as malicious as they seem.
From very different worlds, June and Day have no reason to cross paths - until the day June's brother, Metias, is murdered, and Day becomes the prime suspect. Now, caught in the ultimate game of cat and mouse, Day is in a race for his family's survival, while June tries desperately to avenge Metias's death.
But in a shocking turn of events, the two uncover the truth of what has really brought them together, and the sinister lengths to which their country will go to keep its secrets.
Full of nonstop action, suspense, and romance, Marie Lu has written an exhilarating first novel that is sure to move readers as much as it thrills.