In blood-soaked Tudor England, twice married, accomplished, and educated Katherine Parr (Alicia Vikander), reluctantly agrees to become the sixth wife of the tyrannical King Henry VIII (Jude Law). Her consent to marry him carries great personal risk, given that her predecessors are either vanquished, beheaded, or dead. When Henry appoints her as Regent, the nation's ruler during his absence when he departs to fight overseas, he lays a dangerous path for her. Henry's courtiers, suspecting she's sympathetic to radical Protestant beliefs that have taken root in the kingdom and are a threat to their power, scheme against her and cast doubts upon her fidelity to the increasingly ailing and paranoid King. Once Henry returns to England, his courtiers convince him to turn his fury on the nation's radicals, including Katherine's childhood friend Anne Askew, who becomes one of the scores of people convicted of treason and burned at the stake. Horrified and privately grieving, Katherine finds herself under ever-increasing scrutiny and suspicion. Knowing that even a whisper of scandal might lead to her downfall, Katherine must unleash her own scheme to fight for survival.