The Long Walk by Slavomir Rawicz, biography category
Slavomir Rawicz was a Polish cavalry officer in World War II. He came home on leave and found himself arrested by the Russians for the crime of, well, being Polish. He was kept in prison, but refused to confess. After a few months, he was tricked into signing a confession and shipped off to Siberia for 25 years hard labor. After a horrible trek up into the northern wilderness, he finds himself in a Siberian work camp.
He decides he's not about to spend 25 years there, and makes plans to escape. He enlists six other men, a Latvian, an American, other Poles, and they sneak out in the night. Their escape plan will take them through Mongolia, across the Gobi Desert, up and down the Himalayas, and through India.
It's an incredible story. I couldn't put it down once I got started. Sometimes there were gaps in the story, but it was absolutely gripping. Really worth reading.