The action-packed volatility of Slow Horses makes it one of the best spy thrillers ever.  The fourth season turns the heat up on Jack Lowden's River Cartwright as much of his family backstory is explained, and boy, does he shine.  Season five can't come soon enough. 📺

Enjoyed it a lot. I had not watched any of this show until a few weeks ago and raced through it. Really well done.