Smart and stylish, AMC+’s “Spy City” captures a tumultuous time and place in world history: Berlin just before the forming of the Wall in 1961. The title of the show comes to life in the way writer William Boyd (“Chaplin”) and director Miguel Alexandre present an interlocking story of espionage that brings in multiple operatives from governments around the world. In 1961 Berlin, the Brits, Russians, Americans, French, and Germans vied for power as the city itself was starting to divide even before it literally did so with a wall that stretched dozens of miles. With the kind of complex plot that should appeal to fans of the work of John le Carré and a story of a defector that recalls Steven Spielberg’s excellent “Bridge of Spies,” this is engaging material filled with double-crosses, betrayals, and a general air of distrust. It’s no fun living in Spy City.