Welcome back to American Heroes. I’m your host, Nathan Weiss. Today, we’re stepping away from the distant past to look at a man many of you might recognize from your screens, but whose most harrowing stories happened long before he ever picked up a microphone.

Before he was the master of the "strange, dark, and mysterious," John B. Allen was a Navy SEAL.

John didn't join the military for the fame or the storytelling. He joined for the challenge. After graduating from the University of Massachusetts Amherst, he pushed himself through the grueling forge of BUD/S—Basic Underwater Demolition/SEAL training. He earned his Trident and was deployed as a member of SEAL Team Two.

His service took him into the heart of the conflict in Afghanistan. But the moment that changed everything didn't happen in a massive, cinem ...