As Derby day arrives, Tommy is faced with impossible decisions as he prepares to strike back at his enemies and take the family business to the next level.
Thomas writes a letter to the editor of the New York Times, explaining the situation with the British Intelligence Service and Winston Churchill, who’s having him perform a high-profile assassination on behalf of the crown. He names Chester Campbell and gives the sealed envelope to Ada, who is ordered to mail it if Thomas fails to return from Epsom, where the Derby is being held.
Ada’s new housemate, James, accompanies Thomas to Camden Town where he has a sit-down with Alfie Solomons. Thomas tells James to stand outside, before he goes into the distillery to see Alfie, who has plans of his own. He wants to get Thomas to sign over 100% of his business before he shoots him dead. Thomas responds by revealing that he and James have a grenade trip-wired to a barrel of rum and if anyone other than Thomas walks outside the door, James is to blow up the joint. Alfie can’t tell if he’s bluffing, and after some back and forth, Thomas agrees to give Alfie 35% of his business. Thomas walks out to greet James, who is very much alive. Meanwhile, Thomas has gotten the murder charge against Arthur withdrawn just in time to join the Lees and head off to the races.
Elsewhere, Polly has emptied the company safe, laying a load of cash in front of Michael Gray and telling him to take the money and start a new life for himself away from Birmingham. She would like to persuade him further, but has her own errand to run.
Before they get to the races, Thomas explains to the Peaky Blinders and their gypsy allies that they must take over Darby Sabini's race track licences, and that he will be creating a diversion to distract the police from their actions.
At Epsom, Thomas speaks to May Carleton, telling her that he will meet her when he is done with his tasks for the day. He is just about to kick his plan into gear at the races when he gets accosted by Grace Burgess, who tells him that she is pregnant and carrying his child. He tells Grace that he will meet with her at the end of the day to speak further.
Thomas enlists the help of his secretary, ex-prostitute Lizzie Stark to help him carry out his plan. Her job is to distract Field Marshal Henry Russell by taking him off somewhere private. A packed bar clears as the start of the race is announced, leaving just Thomas and Major Campbell alone. Campbell yet retains his sense of self-deluded righteousness, while Thomas tells him: "Today, it’ll be me dead or you. But whoever it is, they’ll wake up in hell tomorrow."
Thomas’s plan doesn’t exactly turn out as he hoped. He is delayed in getting to Lizzie, who is sexually assaulted by the Field Marshal Henry Russell. When Thomas does arrive, his gun jams, but he grabs his target’s own pistol and shoots Russell dead. The assassination is the diversion that Arthur Shelby Jr., John Shelby and the Peaky Blinders gang need to hold up Darby Sabini’s bookmakers and burn their licenses while the police are distracted.
Thomas's smug showdown with an apparently defeated Darby Sabini is only ruined when Campbell’s hired men rush in and kidnap Thomas, placing him in a vehicle and driving off.
Meanwhile, Grace and May wait for Thomas to turn up but instead find each other. May speaks of the business allegiance she has with Thomas, while Grace reminds her that the horse Grace's Secret is named after herself.
Polly Shelby corners Major Campbell in a phone booth whilst he’s on the phone with Winston Churchill bragging about his successes, and aptly shoots him in the chest. The matriarch strides through the bar with a bloodstain on her dress as behind her, Campbell slumps to the ground dying in the booth.
Thomas is carted out to an abandoned field where he faces certain death. He faces his execution with a mixture of anger at the approaching end to his weary acceptance that death has stalked him much of his life. But after Thomas enjoys his final cigarette, one of the three would-be assassins shoots the other two in the head and leaves Thomas lying in a grave, confused and alive. The man says, “At some point in the near future, Mr. Churchill will want to speak to you in person, Mr. Shelby. He has a job for you.” He tells Thomas to go home.
Back in his office, Michael Gray informs Thomas that he's turned down Polly's money to work for Thomas and make real money. Thomas speaks with him and also makes an announcement that he's planning on getting married.
- Thomas Shelby: "When you plan something well, there's no need to rush."
- Thomas Shelby: "I nearly got fucking everything"
- Ulster Volunteer Force Man: "At some point in the near future, Mr. Churchill will want to speak to you in person, Mr. Shelby. He has a job for you."
- Arthur Shelby: "Who’s gonna stop us, eh? Nobody."
- Thomas Shelby: "You know what, Michael? What Polly wants will always be a mystery to me."