A nationally recognized K9 Unit Officer, Isaac Ho'opi'i is responsible for saving numerous people from the Pentagon during the terrorist attacks on September 11, 2001. Countless articles were written about his heroism following 9/11. He was photographed by Richard Avedon for a spread in USA Today. He appeared on NBC's "Today Show." And he ran the Olympic Torch on its way to Salt Lake City for the 2002 Winter Olympics. "Corridor Four" is a documentary that illustrates Isaac's story in the aftermath of 9/11. After all the news cameras had turned off and all the lights had dimmed, Isaac was left only with the horrific images he had seen and the memory of those he was unable to save. His is a story not of a hero basking in the glory of his past deeds, but of a human being filled with regret that he couldn't change something completely out of his control.