Half the World By Joe Abercrombie

Thorn Bathu was born to fight. But when she kills a boy in the training square she finds herself named a murderer.

Fate places her life in the hands of the deep-cunning Father Yarvi as he sets out to cross half the world in search of allies against the ruthless High King. Beside her is Brand, a young warrior who hates to kill. A failure in her eyes and his own, the voyage is his last chance at redemption.

But warriors can be weapons, and weapons are made for one purpose. Will Thorn always be a tool in the hands of the powerful, or can she carve her own path? Is there a place outside of legend for a woman with a blade?