This is a spy movie. It is set in a very real 1970s, when phones had cords and even spy cameras had film. The Iron Curtain was up and the cold war was on. You had know way of knowing if the guy working next to you (definitely guy and not gal) was actually working for the other side. This is the world of George Smiley.
Therefore, you will find no car chases, no computer hacking, and no super-micro, multi-function spy gadgetry. What you will find are dead drops, false identities, and interrogations and conversations where you talk for hours to see how if the other guy will trip himself up and reveal a falsehood that will let you nail him as a spy. This is the world of George Smiley.
We've been here before. The original books by John le Carré are masterpieces. The British mini-series starring Sir Alec Guiness was nearly perfect. But it is good to be back. The settings, dialog, directing, and acting are picture perfect and harmonious. What doesn't quite come together is the story. If you don't already know it, you will certainly feel lost along the way. You're sure, in the end, that all the pieces to the puzzle must have been there all along. You just didn't pick them up. This is a grown-up movie and doesn't spoon feed you. This is the world of George Smiley.
Tinker Tailor Soldier Spy (IMDb)