The Last Contract of Isako (hardcover) Fonda Lee

Isako is a legendary swordswoman, but every legend must come to an end. When her long-time client unexpectedly retires, she plans to follow—to walk out into the frozen wasteland of their planet with her head held high and her family enriched by her death. But when she's offered a final mission, she can't refuse, especially when she realizes who lies at the center of it Martim, her last—and worst—apprentice, who's somehow made his way to the top. As she's thrust into a world of corporate espionage and shadowy secrets, what she uncovers could forever change humanity's existence among the stars.