Slow Horses is a British dark comedy spy series centered on a group of MI5 (domestic intelligence) agents assigned to Slough House, where they send the rejects who can't be fired because it's the civil service.

Jackson Lamb (Gary Oldman) is the crusty head of the house, amazingly experienced but seemingly hates everyone especially his people, though it turns out he will all he can to protect them. River Cartwright (Jack Lowden) is the newest arrival, a bright field agent who royally messed up during a training run. Diana Taverner (Kristin Scott Thomas) is the ruthless second desk at MI5, Lamb's superior and willing to burn all of Slough House if it will get the job done.

In season one Lamb and crew decide to rescue a Pakistani student kidnapped by British ultra nationalists who plan to behead the kid when it turns out they're interfering with one of Taverner's black ops. In season two one of Lamb's old assets is murdered and Lamb decides to find the killer when MI5 determines the death was accidental.

This is a fairly tense show. Slough House people die. And yet darkly humorous at times as the team tries to do their jobs but are not especially good at it (though I guess mostly it's more lack of experience which Lamb could impart to his agents but doesn't). Each season is six hour-long episodes so the story goes through fairly quickly.

Definitely recommended.