Why did a Polish spy infiltrate Auschwitz?

Witold Pilecki didn’t try to escape Auschwitz. He broke in. For two and a half years he starved, froze, and nearly died. But he never gave in. Sent in as a spy, he built a secret resistance and smuggled out one of the first eyewitness reports of the Final Solution. When he escaped to tell the world, no one believed him. He continued to resist—only to be executed by the Polish Communists. His heroism was erased from history. Until now.