Slow Horses season 4 on Apple TV+ has viewers wondering if Slough House is a real MI5 branch. The British spy thriller is based on the bestselling Slough House series of novels by Mick Herron. Like the source material, the series centers on Slough House the administrative purgatory for MI5 agents who’ve made career-ending missteps. Although these “slow horses” are relegated to drudgery, they get involved in high-profile cases, thanks in large part to the rude-yet-incisive veteran MI5 agent Jackson Lamb (Gary Oldman), who leads Slough House’s team of well-meaning misfits.
https://screenrant.com/slow-horses-true-story-slough-house-real/