Business is booming for the Peaky Blinders, as Shelby starts expanding both his legal and illegal operations. He plans for the future, looking at managing a race track in the South. He soon comes across some new adversaries, testing him in very different ways. Back in Birmingham, Shelby's home town is challenged by members of his family reacting to the upturn in their fortunes. A enemy from his past also returns hoping to exact their plan of revenge of biblical proportions.

Tommy offers to help Polly by searching for her children, who long ago were taken from her. In London, Tommy risks his life by meeting enigmatic leader Alfie Solomons. Meanwhile Arthur continues to feel the devastating effects of the Great War.

The Peaky Blinders are lured by the Italians into a cat-and-mouse chase on the streets of Birmingham. As his factory lies idle, Tommy confronts the possibility that the Communists might win and he will be deemed a traitor to his class.

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.