In Birmingham, Thomas Shelby leads the ambitious Peaky Blinders gang. After the gang acquires stolen weapons, Chief Inspector Campbell arrives to retrieve them, bringing undercover agent Grace Burgess to infiltrate the Shelbys. Tommy, seeking to consolidate power and protect his family, navigates dangerous rivalries and a complex web of deception.

The central conflict revolves around Tommy's efforts to secure his gang's future while dealing with Campbell's investigation and the threat of the IRA. Key turning points include Tommy orchestrating Danny "Whizz-Bang" Owen's faked death to prevent war, and the escalation of the feud with the Lee family, leading to John Shelby marrying Esme Lee. Tommy also begins a relationship with Grace, unaware of her true role. The season culminates in a violent showdown where Billy Kimber is killed, but Grace's fate remains uncertain as Campbell confronts her.

Season 1 of Peaky Blinders covers episodes 1-6. Here's everything that happened:

Season 1, Episode 1: Episode 1 - Thomas Shelby, leader of the Peaky Blinders, inadvertently acquires a stolen consignment of military weapons, prompting Chief Inspector Campbell's arrival in Birmingham to retrieve them. Undercover agent Grace Burgess infiltrates the Shelby's pub as a barmaid. When Danny "Whizz-Bang" Owen accidentally kills an Italian, Tommy orchestrates Danny's faked death to avert gang war. The episode concludes with Tommy consolidating his power, unaware of Grace's true identity as Campbell's informant.

Season 1, Episode 2: Episode 2 - Inspector Campbell's raids for stolen arms yield nothing, while Tommy orchestrates a public stunt to undermine him. Ada's pregnancy with Freddie Thorne is revealed, and despite Tommy's initial disapproval, Freddie proposes to Ada, and they decide to stay in Birmingham. The Shelbys clash violently with the Lee family. Tommy then confronts Billy Kimber, ultimately forging an alliance with Kimber against the Lees. The episode concludes with Tommy inviting Grace to the races, furthering her undercover mission.

Season 1, Episode 3: Episode 3 - Grace kills an IRA man during her undercover investigation. Tommy takes Grace to the Cheltenham races, intending to use her to secure a deal with Billy Kimber. After offering Grace to Kimber, Tommy intervenes to save her from assault. Ada and Freddie marry, defying Polly's wishes to leave Birmingham. The episode concludes with Grace questioning Tommy's motives as they drive away from Kimber's estate.

Season 1, Episode 4: Episode 4 - The Shelby family's feud with the Lee family escalates, prompting Tommy to broker a truce by arranging for John Shelby to marry Esme Lee. At the wedding, Ada gives birth to a son, but the joyous occasion is marred when Freddie Thorne is arrested by Inspector Campbell's men. Tommy, who had offered Campbell a communist's location for Freddie and Ada's safe passage, begins to suspect Grace's loyalties, despite offering her a job and sharing a kiss.

Season 1, Episode 5: Episode 5 - Tommy faces an IRA threat, leading to a violent confrontation where Grace kills an IRA member and Tommy brutally finishes another. Grace reveals the location of the stolen guns to Inspector Campbell, then resigns, but rejects his marriage proposal. Meanwhile, Arthur Shelby Sr. returns, manipulating Arthur Jr. for money, which ultimately leads to Arthur Jr.'s attempted suicide. The episode concludes with Tommy and Grace consummating their relationship, unaware Campbell is secretly watching them.

Season 1, Episode 6: Episode 6 - The Peaky Blinders clash with Billy Kimber's gang. Kimber shoots Tommy, then kills Danny Whizz-Bang. Tommy retaliates, shooting Billy Kimber dead, ending the war. Grace confesses her love to Tommy, but her fate is ambiguous as Inspector Campbell confronts her, and a gunshot rings out.