This is one of the most gripping and intelligent tv shows ever. Every single episode is riveting to the point that it's extremely hard not to keep watching the next one without interruption. The way so many characters--people we really care about--die makes MI 5 one of a kind in terms of credibility. And yet they are all replaced so smoothly that we soon forget them. There's no room in the stories for sentimentality. That affects the characters and also the audience, as we feel ourselves being dragged ever more deeply into Harry Pearce's spy world, imagining ourselves having to make heart-wrenching and incredibly courageous choices. Self-sacrifice never looked so good. The plots seem real and are full of surprises, with each episode a cliff-hanger. I find myself feeling both tense and oddly satisfied at the end of each one. I truly hope that the series will be revived, as its creator wishes.