Following the passing of Henry VIII, his three children; Mary, Elizabeth and Edward are now pawns in a dangerous game as the English court is plunged into a race for control of the new England they find themselves in. With Spain circling, the nine-year-old Edward takes the throne, with his uncle, the Duke of Somerset, becoming both mentor, and representative as Lord Protector. As de facto king, Somerset, along with his oldest friend John Dudley, try to secure a victory in Scotland to secure the new king's reputation. Meanwhile, the Lord Protector's brother - Thomas Seymour - pursues a different route to power; the Queen Dowager Catherine Parr... who has just taken the Princess Elizabeth into her home. Elizabeth is unsure who to trust, but is quickly enamoured with the charming Thomas, imagining him a possible husband, little knowing he is on his way to becoming her stepfather.

Christmas at court, and a controversial masque leaves Protestant Edward and Catholic Mary at odds. Elizabeth finds herself in the middle as Mary, furious at Catherine's remarriage, demands she leave them both and come live with her. Thomas's brother the Lord Protector Somerset tries to keep the peace between the siblings as Pedro returns from Scotland with the news of French invasion as tempers fray at the newly formed court. At home Elizabeth is torn between duty to her sister, her love for Catherine and the growing attention of Thomas which both excites and scares her. As the Dudley family join the Chelsea household for a hunt, and Elizabeth is reunited with childhood friend Robert Dudley, she finds herself left with a choice about where she wants to stand in this world, and who she wants to be.

Elizabeth's decision to side with one sibling leaves the Lord Protector Somerset trying to maintain the balance between the two opposing religions. As Catherine's sworn enemy the Catholic Bishop Stephen Gardiner is released from the Tower, Elizabeth is horrified by the chain reaction she has unwittingly begun. Catherine and Thomas blame Elizabeth as they panic that the game is sliding out of their control. Having felt canny to the ways of court and politics, Elizabeth is left feeling very young and more aware than ever of how precarious peace in England is. But when Catherine and Thomas plan a large celebration for her 15th birthday she is relieved to think she is back in favour with them both, little knowing her step-parents see it as a chance to bring the court and king to Chelsea, and enact their plans to have Jane marry Edward.

Having been sent away from Catherine and Thomas' household, Elizabeth is amongst strangers in the house of Kat's brother-in-law Antony Denny, and terrified of anyone finding out her secrets from Chelsea Place. Pregnant Catherine and Thomas put on a united front to the court and the king, staring down the gossip surrounding Elizabeth's exile. As the rumours spread, Robert tries to defend his friend Elizabeth in her absence leaving his father the Lord Dudley questioning his friendship with the Princess. Thinking he has Mary under control, the Lord Protector Somerset allows Edward to pursue his Protestant faith. However, he is met with resistance from an unlikely place, as Catholic Pedro questions whose side the Lord Somerset is really on.

Elizabeth, changed by her experiences, is determined to not fall into the same traps she did when last she was at Chelsea, but the return of Thomas into her life is a new test for her. While the court has been rocked by Mary's defiance, the Lord Somerset is still more concerned with raising funds for the war in Scotland. As rebellions spring up across the country, a secret meeting with the French Ambassador, without the knowledge of the council or the king, sees even his closest friend, the Lord Dudley, begin to doubt Somerset's strategy. As the Lord Somerset starts to lose the trust of even those close to him and with the king's growing hatred of him, Thomas sees a chance to end the rule of the brother he believes has always kept him down. And Elizabeth is key to his plan.

Thomas' actions have implicated Elizabeth, and whilst under house arrest, Elizabeth must clear her name as she is interrogated by the Lord Dudley. The Lord Somerset is rocked by his brother's actions, and with Thomas in the Tower, faces the furious council and the badly shaken king who demand action. Mary comes to London to face her disgraced little sister, and Elizabeth finds herself out of favour once again as Mary comforts Edward after his ordeal. As the rebellions reach a peak in Norfolk, Somerset sends the Lord Dudley and his sons to crush it. Elizabeth is left without Robert and the Lord Somerset is left without an ally, which the council takes full advantage of, deciding it might be time for a new Lord Protector, or perhaps, a Queen Regent instead.

It's a new age with a new Lord Protector, and Edward, now free from his uncle Somerset's influence is emboldened to pursue ever more ruthless Protestant reforms and to seek new alliances.

The king is sick and the court that made an enemy of Catholics now faces the possibility of being ruled by one as Mary rides to Whitehall. Mary and Elizabeth are briefly reunited in their love for their sick brother, but Edward is distraught that his legacy of a Protestant England dies with him if Mary succeeds to the throne. Elizabeth watches as the court breaks old loyalties and forms new alliances with every man desperately scrambling to survive what may be coming. That is until Elizabeth is approached with the proposition: if England is to see its first woman on the throne, why should it not be her?