The first, and perhaps best novel by John Le Carre, and movie based on it.  It stars Richard Burton in the lead role in an incredible performance. It is the quintessential cold war spy movie.  It is the anti-James Bond film.  Instead, it is film noire realism of what being a double-agent in a divided Berlin at the height of the cold war was like, written by a spy who had been there.  The dividing line between us and them is difficult to determine.  This movie starts quietly and gradually tightens the spring until the final scene.  It  packs a real punch, and is not soon forgotten.