Four-part drama series inspired by the historical events of 1666 and focusing on events which led to the catastrophic fire. Thomas returns to the city in search of Sarah to see the fire spreading with alarming speed across the capital. In Whitehall, the King is angry to learn that his orders to create fire-breaks have been ignored by his advisors. Meanwhile, Lord Denton realises that James, Duke of York, is the mastermind behind the plot to assassinate his brother the King. Elizabeth Pepys confronts her husband about his infidelity with Mrs Bagwell, but Pepys pleads ignorance. Thomas finally finds Sarah on the streets, hiding from Denton's men, and together they find shelter from the inferno.