The Last Contract of Isako Book by Fonda Lee

The novel follows Isako, a veteran corporate samurai on the harsh, frozen planet of Aquilo. Known as a legendary swordswoman, Isako intends to retire—which, in her world, traditionally means walking into the frozen wilderness to die so her family can receive her death benefits.Instead, she is pulled back for one final mission involving her former apprentice, Martim, who has risen to a position of significant power. The job thrusts her into a web of corporate espionage and dark secrets that could alter humanity's future among the stars.