The action has moved on two years to 1924 and as Tommy starts married life he is more determined than ever to go legitimate and keep his family safe. But he finds himself pulled into a web of intrigue more lethal than anything he has yet encountered.
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.
Tommy travels to Wales seeking absolution, and uncovers a traitor in the Economic League. Michael develops a taste for guns. Arthur gets good news.
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.