Slow Horses season 4 adds Hugo Weaving and more – and season 3 hasn't even aired yet

Slow Horses season 3 hasn't even aired yet, but that hasn't stopped the Apple TV Plus series from announcing the new cast members it's set to welcome in season 4.

According to Deadline, the Gary Oldman-led spy thriller, which is currently filming its fourth chapter in London, has added Joanna Scanlan (The Thick of It), Ruth Bradley (Humans), Tom Brooke (Bodyguard), and James Callis (Bridget Jones's Diary), as well as Marvel and Lord of the Rings star Hugo Weaving to its line up. While character details remain under wraps, we do know that I See You's Adam Randall will be directing the new episodes and that the installment will "open with a bombing that detonates personal secrets, rocking the already unstable foundations of Slough House."

Based on Mick Herron's Slough House series, the darkly comedic show was adapted by Veep's Will Smith and centers on Jackson Lamb (Oldman), the cantankerous leader of a team of MI5 employees who have been assigned to dull, paper-pushing tasks following a series of career-ending mistakes. The ragtag group find their drudgery-filled lives get more exciting, however, when they somehow get involved in investigating schemes endangering Britain.

Its existing ensembles consists of Jack Lowden, Saskia Reeves, Rosalind Eleazar, Christopher Chung, Freddie Fox, Chris Reilly, Samuel West, Sophie Okonedo, Aimee-Ffion Edwards, Kadiff Kirwan, Jonathan Pryce, and Kristin Scott Thomas. It was renewed for seasons 3 and 4 back in June 2022, before the second season had even be released.

Slow Horses season 3 will likely premieres on Apple TV Plus in late 2023. In the meantime, check out our list of the best Apple TV Plus shows available to stream right now.