In the face of terror bombings, right-wing extremism, rogue operations, and sleeper KGB agents, the true villainy in Slow Horses is all the things MI5 does in the name of security and of preserving itself. Though its brass would often prefer to toss its trash into Slough House (figuratively but sometimes also literally), secrets bubble to the surface. In season four, this becomes more personal than ever. 

Although all of the slow horses are sentenced to Slough House against their will, Lamb relishes his state of semi-­retirement (though perhaps not his responsibilities as warden) as well as the maneuverability it gives him. Lamb answers to no one and gets involved only when he feels like it. If spycraft is about information—manipulating, uncovering, or inferring it—Lamb is the genius always one or two steps ahead. If he has a code, it is the code of spycraft: Even if he loathes them, he protects his people. 

Jackson Lamb is the show’s most distinctive creation, and Gary Oldman its biggest star. In his image, the show coalesces its tone, point of view, and position in the marketplace. Lamb is a tortured male genius in a way that feels almost old-fashioned, made so distasteful that it feels novel. He is sarcastic and blunt and hostile to propriety. He acts like everyone is an idiot slowing him down, and they usually are. For a show in which characters relate to one another through the art of the insult, Lamb is at the top of the heap. He’s a Malcolm Tucker who doesn’t shower, a Logan Roy with no ambition, a Larry David without the irony. 

Oldman’s Lamb is not exactly unprecedented; he’s just extreme. He’s the driving force and also the vehicle for a base, lowbrow humor, lest you start to take the show too seriously. Our first image of Lamb is of the holes in his socks; his first expression is a fart. In the third season we witness his version of a shower, which amounts to filling a cramped sink and splashing his pits with tepid water. As you might guess, Lamb’s personal hygiene and appearance belie his wit and competence. 

Lamb’s capabilities are most often on display in his interactions with the leaders from MI5. The show relishes putting Oldman’s slovenly figure opposite Kristin Scott Thomas’s crisp and businesslike Diana Taverner. Taverner is “second desk,” or second-in-command, at MI5, and she’s often behind whatever shitstorm threatens to rain down on Slough House. While the other characters focus on the pieces in front of them, Lamb and Taverner play the whole board. But the show would stumble without actors of the stature seen here. Like Pryce’s David Cartwright flitting in and out of lucidity, Taverner only has whatever gravitas Scott Thomas brings to the role. That’s because for all her apparent ambition, Taverner is a character with simple aims: She merely wants to advance her career to the next spot above her current one. Like the MI5 itself, she exists only for her own preservation and advancement. Taverner is always politicking, but with no politics.

Depending on your point of view, this is either a feature or a bug of the series as a whole. Even in the first season, when a white-nationalist terrorist organization forms the immediate threat, the group’s politics are so cartoonish as to be toothless; its views exist only so that we may dismiss them. Peter Judd (played by Samuel West as a sleek version of Boris Johnson) makes the appropriate incendiary comments, but who knows what he actually believes. Belief isn’t something that enters Taverner’s mind either, or that of Sophie Okonedo’s Ingrid Tearney (the director, or “first desk,” of MI5) when she negotiates with or attempts to outmaneuver Judd. There are no true believers in Slow Horses, no one doing it for the love of duty or country, just as there is no real political view behind any character or action of consequence. 

In the same way the spycraft in Slow Horses strives to be unfantastical, the show’s politics are unphilosophical; Lamb and Taverner’s arguments are strategic, not existential. Lamb is an acceleration and a step backward. He is a test of how detestable you can make a character and still be entertained by him. Lamb has crafted himself into the ultimate misfit and outcast of the system, but without a critique of the system, and of course no critique of his own role in it. 

And through four seasons at least, there’s been no risk of that pesky self-awareness coming around the corner. But that suits the show just fine. Details like that would bog it down, or at least give us more to think about—and that’s not what Apple TV+ is aiming for. As with its other recent successes (see Hijack and Presumed Innocent), the streamer is serving up the aesthetics of prestige with the pulpy, twisty pleasures at which TV has always excelled. 

On this measure, Slow Horses is a triumph. You can watch it with your roommates, your parents, or your grandkids. It’s funny, tonally consistent, serialized yet self-contained. Each season of the show boasts a different director, but you won’t notice unless you’re looking for that. It’s sleek, but not stylish; it’s grimy, but in a cool, clean way. And though it’s a show that relishes banter and verbal sparring, the action set-pieces are what truly draw you in: tragic chase sequences, attempted heists, infiltrations, sieges, and shootouts. Beneath its fanfare of sharp elbows and dyspeptic discontent, Slow Horses intends to go down easy. Like Jackson Lamb in Slough House, there are benefits to just being the sideshow.