Having narrowly escaped enslavement at the hands of the Black Castle, Taryn and Emmett find themselves houseguests of the strangely familiar Lord Erikkson. His claims of benevolence, however, ring hollow amid suspicions of an ulterior motive. Lord Erikkson calls Taryn "Sedition" and says she was built to lead a biomaton rebellion, yet she has no desire to fulfill this role.

But rumors of a mysterious assassin biomaton abound, and with the treatment of biomatons laid bare, Taryn must choose between enslavement and risking her life to become the leader her creator intended. Further complicating matters, Emmett is grappling with sightlessness, and Ace has gone missing, leaving Taryn to juggle caring for her friends with an impossible choice. When Lord Erikkson offers to help one of them in return, she is hard-pressed to refuse to pick up his sword.

Becoming Sedition will mean Taryn must fight to earn every scrap of respect and power needed to achieve her goals. And indeed, the price of freedom is very steep.