Confession time: I’d never read any John LeCarré until after I’d seen the 2011 film of Tinker Tailor Soldier Spy. It’s a brilliant movie, and one that sent me scuttling to read the Karla trilogy and then watch the two excellent Alec Guinness adaptations. After devouring the first two episodes of Apple TV+’s Slow Horses, I can think of no higher compliment than to say that I’m bulk-buying the book series it was adapted from in short order.

Slow Horses is an adaptation of Mick Herron’s series of Slough House novels, featuring a group of British spies trapped in administrative purgatory. MI5 agents who have committed high-profile mistakes but know far too much to be fired are dumped in the dingy Slough House. There, they are given harmless busywork too demeaning for real spies to undertake, all the while being tormented and demeaned by division chief Jackson Lamb, played by Gary Oldman.

It’s this world that former superstar spy River Cartwright (Jack Lowden) is thrust into after his own notorious error while out in the field. There, he’s given jobs like searching a dodgy journalist’s trash can and acting as a courier between offices. It’s hardly a spoiler to suggest that Cartwright’s arrival triggers something of a major case for the rejects to handle, which has mostly kicked off by the time the second episode finishes.

What Slow Horses has to offer, beyond the enjoyment of a modern-day thriller done right, is a sense of pulpy fun. A sequence in the second episode I can’t spoil plays out with the beats of a Chuck Jones cartoon rather than an entirely gritty espionage potboiler. It helps, too, that the show isn’t trying to make everyone a two-dimensional cut-out, which can so often be the case when prestige TV attempts to make spy-fi.

The series was created by the unfortunately named Will Smith, the British standup, actor and writer who, far as we know, has never slapped Chris Rock on stage. The dialog sparkles, not surprising given that Smith has written for Avenue 5, Veep and The Thick of It. It’s also clear-eyed about its politics, offering something approaching nuance concerning the benefits and burdens of living in a surveillance state.