Slow Horses Season 4: Apple’s magnificent spy drama delivers some of the best TV of the year

It's always been the little details that stand out in Slow Horses, the long-running Apple TV+ spy drama that returns on Sept. 4. For one thing, viewers can practically smell the mold and feel the dust that pervades 126 Aldersgate Street in London -- also known as Slough House, the depressing outpost to which the so-called Slow Horses of MI5 have been summarily banished in lieu of a pink slip. Save for computer whiz Roddy Ho's setup downstairs, it's a low-tech office that stays fastidiously untidy with overflowing trash bins...