If you ask people why the Berlin Wall came down so unexpectedly, those who remember those days might tell you it was because of President Ronald Reagan’s famous “tear down this wall” speech. Many forget that address took place more than two years before Germans put sledgehammers and pick axes to the cement barrier as the beginning act of their reunification. Now, after a quarter of a century has passed, a story has begun to circulate about what really happened. It’s a tale of a mysterious group with ties in many countries, a billionaire industrialist, the CIA, Stasi thugs, goosestepping East German soldiers, a Nazi general, massive disinformation — and murder. In the middle of the story is a Chicago homicide detective who gets tossed into those whirlwind times and becomes key to them all.