The show centers on , a dumping ground for MI5 service members who have committed career-ending mistakes. These intelligence officers are derisively nicknamed "Slow Horses." They are forced to endure boring, bureaucratic tasks under the supervision of their miserable boss, hoping to eventually be transferred back to the glamorous "Regent’s Park" headquarters.

His portrayal of Jackson Lamb is a masterclass in "anti-hero" acting. He is gross, rude, and somehow entirely captivating.