[1] The season has Queen Mary Stuart returned to Scotland and trying to regain power in her torn homeland.

She has to manage her allies, such as her bastard half-brother James and the outspoken Lord Bothwell, as well as her enemies, such as the Protestant preacher John Knox.

Mary is ready to accept, but changes her mind after meeting Lady Lennox, who shares her past experience of being Elizabeth's prisoner.

Mary writes to Elizabeth in kinship, asking her to protect her son and accept him as heir to a united Scotland and England.

Darnley is mentally unstable due to syphilis; he hallucinates Keira, and flees the castle with his son.