Allied — Amy Tintera

In the final book in the New York Times bestselling Ruined series, the romance of The Selection and the epic stakes of Red Queen come together in a story of revenge, adventure, and unexpected love.

Emelina Flores and her sister, Olivia, were determined to bring peace to the people of Ruina. But as the war for liberation raged on, what triumph and freedom meant to Em and Olivia slowly changed. As Olivia's violence and thirst for vengeance became her only ambition, Em was left to pick up the pieces.

But it's not only Em who is upset by Olivia's increased violence. Other members of the Ruined army are beginning to see the cracks, and soon a small group of them defects from Olivia's army and joins Em instead.

The two sisters are soon pitted against each other in an epic battle for the kingdom and the future, and only one will win.