Slow Horses will return for a fifth season on Apple TV+. The streaming service announced that it renewed the spy drama starring Gary Oldman for Season 5. Slow Horses is based on the Slough House book series by Mick Herron. The show follows Jackson Lamb (Oldman) and his dysfunctional team of MI5 rejects, known as the Slow Horses. Apple TV+ has yet to announce premiere dates for Season 4 and Season 5.