Watch: The trailer for 'Slow Horses' season 6 has galloped in

One of Apple TV's most celebrated shows returns next month—and we've got the trailer to hype you up.

The six-episode sixth season of Slow Horses premieres on September 16, with the Slow Horses on the run as Diana Taverner throws them all in a "fatally high-stakes game of retaliation and revenge," the logline reads.

RECOMMENDED: Kit Harrington is starring in an adaptation of one of Charles Dickens’ most famous works

What is Slow Horses about?

Adapted from Mick Herron’s Joe Country and Slough House, the dark but dryly humorous spy drama follows "washed up" and "failed" MI5 agents led by Jackson Lamb (Sir Gary Oldman) who defend England against its enemies. According to Apple, all five seasons have a Certified Fresh score, with two seasons receiving a rare, perfect 100 percent critics’ score on Rotten Tomatoes. The fifth season alone earned nine Primetime Emmy Awards, including a nod for Outstanding Drama Series, and nominations for Gary Oldman and Jack Lowden for Outstanding Lead Actor and Outstanding Supporting Actor, respectively.

Watch the Slow Horses season 6 trailer below:

Who is in the cast of Slow Horses season 6? 

The ensemble cast includes Academy Award nominee Kristin Scott Thomas, Emmy nominee Jack Lowden, Saskia Reeves, BAFTA TV Award nominee Christopher Chung, Aimee-Ffion Edwards, Rosalind Eleazar, Joanna Scanlan, BAFTA nominee Samuel West, Ruth Bradley, Tom Brooke, Academy Award nominee Jonathan Pryce and Hugo Weaving.

BAFTA TV Award winner Lenny Rush is a new addition for the sixth installment; Olivia Cooke will also reprise her role as Sidonie “Sid” Baker in the sixth season. 

When will Slow Horses season 6 premiere?

The first episode drops on Wednesday, September 16 and will be followed by one episode weekly until October 21 on Apple TV.