Union Station by David Downing

In this fascinating historical thriller, a British journalist (and former spy) is adrift in McCarthy-era Los Angeles-until his research into a wartime conspiracy brings him face-to-face with the perilous instability of a post-Stalin Berlin.
John Russell, an English journalist who specializes in human-interest pieces, had always been a reluctant spy. It's a dangerous life-especially when you are tasked with being a double agent for Soviet and American intelligence, in a city as fraught with hazard as Nazi-occupied Berlin. But it's been years, now, since Russell was finally able to extricate himself from his life of espionage-through a shady deal with a high-ranking Soviet official.
Now it's 1953, and Russell and his family-his long-time partner, Effi Koenen, a burgeoning star on an American sitcom, and their daughter, Rosa, a young artist on the cusp of adulthood-live a life of relative comfort in Los Angeles. Feeling somewhat adrift, Russell has just begun work on a book investigating American firms that continued doing business with Germany during Nazi occupation. Then he notices someone is tailing him around Los Angeles. Has someone not taken kindly to his research? Or could it be that the deal Russell struck all those years ago has left him with unfinished business?
The answer may lie in Berlin, where John and Effi decide to return for the Third Annual Berlin International Film Festival. Braving the political disorder of a city that was once their home, the two are thrust into a perilous mission to protect the life-and safety-they worked so hard to build.