As the 1920s begin to roar, business is booming for the Peaky Blinders gang. Tommy Shelby starts to expand his legal and illegal operations, with an eye on the racetracks of the south. Meanwhile, an enemy from Tommy's past returns to Birmingham.
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.
Tommy hatches a plan to take control of the southern racecourses. He also meets the aristocratic May Carleton, and sees an opportunity to move up in the world. Meanwhile both Major Campbell and London gangster Darby Sabini plan Tommy's downfall.
Tommy finds out exactly what mission Major Campbell is forcing him to undertake. Arthur spearheads a ferocious takeover of London's Eden Club. Meanwhile, Polly's son Michael is welcomed into the business, and quickly experiences the dark side of the Peaky Blinders.
Tommy is caught by surprise when his powerbase in London is obliterated. As Tommy struggles to save his family and regain the upper hand, May expresses her feelings for him, and he is paid a visit by an old friend.
As derby day arrives, Tommy is faced with impossible decisions as he plans to strike back at his enemies and take the family business to another level. Meanwhile, Major Campbell has one final card to play - one that he is certain will bring about Tommy's demise.
It is Thomas Shelby's long-awaited wedding day. In the middle of the celebrations, a mysterious visitor imperils the entire Shelby family, and Tommy finds himself pulled into a web of intrigue more lethal than anything he has yet encountered.
Tommy discovers the extent of the mission given to him and the extreme lengths his new paymasters are willing to go to in their quest for power. Meanwhile his own family's activities lead to escalating danger in Birmingham.
Responding to the Italians' actions, Tommy is set on a path of deadly vengeance that could take him to his darkest place yet, and threatens to splinter the family. Meanwhile, as he makes plans for his mission on behalf of the Russians, he realises there is a traitor in his midst.
Tommy and Tatiana play a personal and dangerous game to acquire information from one another, and Tommy finally comprehends the magnitude of Tatiana's warped ideals. Meanwhile, Polly reveals a dark secret, with terrible consequences for Tommy.
As the Russians test the Peaky Blinders, Tommy realises that he is being seriously outmanoeuvred. But he has an ace up his sleeve in the form of an enemy turned ally - if only he can control him.
Birmingham, 1919. Thomas Shelby controls the Peaky Blinders, one of the city's most feared criminal organisations, but his ambitions go beyond running the streets. When a crate of guns goes missing, Thomas recognises an opportunity to move up in the world.
Thomas fixes a horserace, provoking the ire of local kingpin Billy Kimber. He also starts a war with gypsy family the Lees. Meanwhile, Inspector Campbell carries out a vicious raid of Small Heath in search of the stolen guns.
Thomas Shelby plans to go to Cheltenham races in order to get closer to Billy Kimber. Knowing the gangster's appetite for beautiful women, Thomas invites Grace to accompany him. Meanwhile some IRA sympathisers approach Thomas with an offer to buy the stolen guns.
Thomas Shelby's war with the Lee family of gypsies escalates, and Campbell puts further pressure on him to deliver the stolen guns. Meanwhile Thomas's brother John plans to marry a former prostitute, but Thomas suspects that she's still on the game.
Thomas Shelby has to deal with an IRA chief who has come to Small Heath to avenge his cousin's death. Meanwhile Campbell gets closer to the stolen guns, and Grace has to decide whether her loyalties lie with him or with Thomas.
As Thomas Shelby prepares to oust Billy Kimber, hidden secrets are revealed and the family have to face up to the problems that have divided them. Meanwhile, Campbell, obsessed with taking down the Peaky Blinders, unleashes one last plan to destroy them.