For 25 years, one name has dominated the story of 9/11. Osama bin Laden. But behind the broader vision of the attacks was another man, far less known to the public. His name is Khalid Sheikh Mohammed, the architect of the plot who currently sits at a high confined prison in Guantanamo Bay. His trail stretches back to the first bombing of the Twin Towers, through the ambitious Bojinka plot and ultimately to 9/11 itself.