December 1925. When Tommy receives a mysterious letter on Christmas Eve, he realises that the Shelbys are in danger of annihilation.

Tradition weighs upon Arthur as Changretta finds a chink in the Shelby armour and Changretta continues to plan ways to continue the vendetta in the most devastating way possible.

It is the night of the big fight - Bonnie Gold versus Goliath. But as the bell rings and the crowd goes wild, dangers lurk in the shadows for Tommy Shelby and his family. When Changretta plays his final ace, he sets in motion a series of events that will change the Peaky Blinders forever.