Slow Horses season 4 release schedule: All episodes and when they arrive

The first episode of Slow Horses season 4 has premiered. The Apple TV+ production, starring Gary Oldman, is an adaptation of Mick Herron's Slough House series of spy novels that were first published in 2010.

The series follows a cast of disgraced MI5 agents who've been relegated to menial desk work and drudgery, with their boss, Jackson Lamb, expecting them to quit out of frustration or boredom.

Nonetheless, even MI5 rejects can get involved in major espionage plots that threaten the security of Great Britain, making them unlikely national security heroes whenever that time comes.

The series first premiered in 2022, with the fourth season premiering on September 4, 2024. The first two episodes were released simultaneously on this day, titled "Identity Theft" and "A Stranger Comes to Town." The remaining four episodes will release on a weekly basis every Wednesday until October 9, 2024.

---

Slow Horses season 4 release schedule

Below is the release schedule for all six episodes of Slow Horses season 4:

Episode	Release date	Release time
Identity Theft	September 4, 2024	12:00 am ET, 5:00 am BST, 9:30 am IST
A Stranger Comes to Town	September 4, 2024	12:00 am ET, 5:00 am BST, 9:30 am IST
Episode 3	September 11, 2024	12:00 am ET, 5:00 am BST, 9:30 am IST
Episode 4	September 18, 2024	12:00 am ET, 5:00 am BST, 9:30 am IST
Episode 5	September 25, 2024	12:00 am ET, 5:00 am BST, 9:30 am IST
Episode 6	October 2, 2024	12:00 am ET, 5:00 am BST, 9:30 am IST

---

Slow Horses season 4 cast and characters

Slow Horses stars Kristin Scott Thomas as Diana Taverner. (Image via Apple TV+)

The main and supporting cast that are part of Slow Horses season 4 are as follows.

Main cast

• Gary Oldman as Jackson Lamb, the chief of the Slough House who has a prickly demeanor and is an overweight alcoholic who dines himself on Chinese takeout. While his Slough House underlings consider him a nightmare to work with, he has a secret sense of loyalty to them.
• Jack Lowden as River Cartwright, a once-promising MI5 agent whose career crashed and burned thanks to a training exercise fiasco at the Stansted Airport.
• Kristin Scott Thomas as Diana Taverner, MI5's deputy director general of MI5, who is the service's operational commander. She's eyeing a promotion to become director general.
• Jonathan Pryce as David Cartwright, a retired MI5 agent and River Cartwright's grandfather. He used his influence to protect his grandson's career after the Stansted Airport incident.

Supporting characters: Slough House members

• Saskia Reeves as Catherine Standish, a recovering alcoholic and officer administrator who butts heads with Jackson Lamb.
• Rosalind Eleazar as Louisa Guy, an MI5 agent assigned to the Slough House after a botched tail operation.
• Christopher Chung as Roddy Ho, a brilliant but insufferable hacktivist who serves as a tech whiz for the Slow Horses.
• Aimee Ffion Edwards as Shirley Dander, an agent assigned to the Slough House due to her anger and drug issues.
• Kadiff Kirwan as Marcus Longridge, a Slough House agent with a gambling addiction.
• Joanna Scanlan as Moira Tregorian, a Queen of the Database who was shafted to the Slough House thanks to Claude Whelan.
• Tom Brook as J.K. Coe, a former Psych Eval operative and the newest addition to the Slough House.

Supporting Characters: Other

• Hugo Weaving as Frank Harkness, a mercenary who used to work for the CIA.
• Ruth Bradley as Emma Flyte, the new head of the "Dogs," MI5's armed tactical wing.
• James Callis as Claude Whelan, the new Director-General of MI5, responsible for Moira's demotion.
• Sean Glider as "Bad" Sam Chapman, a private detective who was formerly Head Dog and David Cartwright's bodyguard.

---

Slow Horses season 4 adapts the Spook Street novel

Jonathan Pryce has an expanded role in Slow Horses season 4. (Image via Apple TV+)

Apple TV's Slow Horses season 4 will be an adaptation of Spook Street, the fifth installment in Mick Herron's Slough House novel series.

The plot of the season follows a bombing at London that puts Diana Taverner in the line of fire. The season will also explore the relationship between River Cartwright and his grandfather, David Cartwright.

David found himself at the center of the maelstrom in the Spook Street novel, as his past came back to haunt him. The fact that the character was promoted to series regular in Slow Horses season 4 seems to be an indication of his increasing prominence in the Apple TV adaptation as well.

---

Slow Horses airs on Apple TV in all regions. A subscription is required for viewing.