You are now listening to World War 2 Stories. I'm your host Steve Matthews. Today, we're going to explore one of history's most chilling atrocities and the remarkable half-century conspiracy to conceal it from the world. This is the story of the Katyn Massacre – a crime so devastating and politically inconvenient that governments on both sides of the Iron Curtain would spend decades burying the truth alongside its victims.

In the spring of 1940, approximately 22,000 Polish military officers, police commanders, intellectuals, and civil servants were systematically executed with a single bullet to the back of the head. Their bodies were dumped into mass graves in the forests of western Russia. The perpetrators weren't the Nazis, as the world would be told for decades, but rather the Soviet NKVD – Stalin's secret police – acting on direct orders from the highest levels of Soviet leadership.

The subsequent cover-up would span fifty years, involve three superpowers, and demonstrate the brutal calculus of wartime alliances and Cold War politics. This is a story about how truth becomes the first casualty of war, and how sometimes, even the victors participate in burying history.