"In August 1989, a group of Hungarian activists organized a picnic on the border of Hungary and Austria. But this was not an ordinary picnic--it was located on the dangerous militarized frontier known as the Iron Curtain. Tacit permission from the highest state authorities could be revoked at any moment. On wisps of rumor, thousands of East German "vacationers" packed Hungarian campgrounds, awaiting an opportunity, fearing prison, surveilled by lurking...