This is one of the best shows on tv. I discovered it two years ago while watching a Masterpiece presentation. Haven't missed an episode since. I prefer shows like The Americans, The Walking Dead, Fargo, etc. but this one struck a chord somewhere in the depths of my psyche and I instantly liked the stories, the scenery of 1960's London and all of the characters. This is television at its best.
An update, my favorite tv night is watching Call the Midwife and Billions back to back. That pretty much covers humanity from A to Z. Writers on both shows deserve A+'s and the actors do too. Keep 'em coming and I'll keep watching.
