‘Slow Horses’ Review: Bucking the Odds

In the television universe, the arc of nearly every series bends toward repetition and gradual decline. The best and most original shows are not immune to this rule (if anything they are more prone to it), no matter how much we would like to tell ourselves otherwise or how willing we are to accept less vibrant versions of a great first season.

I did not want to believe this would be true of the satirical British spy thriller “Slow Horses,” whose first two seasons on Apple TV+ were a terrific blend of mordant, melancholy comedy and absorbing action and mystery, not quite like anything else on TV. Maybe the third season, which felt more concerned with plot mechanics and violent set pieces than character, was a hiccup.

Season 4, based on “Spook Street,” the fifth book in Mick Herron’s Slough House series, does represent a slight comeback. (Two of six episodes are at Apple TV+.) But it still has a feeling of going through the motions and casting about for new ideas. How many times can the beleaguered hero, River Cartwright (Jack Lowden), chase and be chased through London railway and Tube stations? The wait for more of the squirmy, transgressive excitement of the early seasons continues.

On the other hand, it is also true — as any number of fans, apoplectic as they read this, will tell you — that “Slow Horses” remains one of the most entertaining and well-put-together shows around. The motions through which it goes are good ones. (In accordance with another general rule of American TV, it is the inferior third season that has finally broken through at the Emmys, with “Slow Horses” up for nine awards including outstanding drama series.)

The irresistible premise remains in place. River is one of a motley group of agents from the British intelligence service MI5 who have been exiled to a backwater called Slough House after catastrophically screwing up their careers. They are expected to keep quiet and do nothing, but under the leadership of their unsociable, unhygienic boss, Jackson Lamb (Gary Oldman), they continually outsmart and outmaneuver their more reputable colleagues and prevent disasters from befalling the agency and the nation.

The new season retains the obstreperous, excitable River along with the no-nonsense Louisa (an excellent Rosalind Eleazar), the Mutt-and-Jeff action team of Shirley and Marcus (Aimee-Ffion Edwards and Kadiff Kirwan), the timorous old pro Catherine (Saskia Reeves) and the inexcusably gross, though often helpful tech whiz, Roddy (Christopher Chung). New to the team is J.K. (Tom Brooke), a cipher in a hoodie who does not add much, even when he grudgingly starts to open up later in the season.