On his 28th birthday, Aaron Ralston scattered the ashes of his own amputated arm in the Utah canyon that nearly killed him. This episode goes far beyond the famous amputation to examine the ambition, the escape, and the messy psychological aftermath of surviving the unsurvivable.

From his Carnegie Mellon engineering background and burnout at Intel to a grade-five avalanche warning he ignored, we trace how Ralston came to be trapped by an 800-pound boulder in Blue John Canyon, and how an engineer's mindset ultimately let him break his own bones to get free.

• Why he told no one where he was going before canyoneering alone
• Rationing 12 ounces of water and two burritos over six days
• The hallucination of a future child that convinced him he would survive
• How dehydration chillingly prepared his body to survive th ...