For decades, the Corner House stood as a silent reminder of Russian oppression. Now, the former KGB headquarters are open and exposing the horrors committed against the people of Riga. It’s like the plot of one of those dystopian young adult novels. There’s a sudden rapping at the door in the middle of the night. A stoic man in a trim suit hands you a warrant. Before you can open the crisp envelope you’re escorted to an imposing structure in the center of town. You’re led inside, and you disappear—never to be heard from again. For years, this was the...