In this episode, we will look back through time, on the 20th anniversary, at missed signals that led to the unimaginable tragedy of September 11th, 2001. And we will look at the heroes who prevented a greater tragedy on that day. 

We first look at Rick Rescorla, who foresaw the attack and led more than 2,600 Morgan Stanley employees to safety, even at the expense of his own life.

What If World History looks at the missed signals that would have uncovered the hijacking plot. And we will highlight the heroes who saved lives and comforted survivors.

And then we will imagine the success of Operation Trident, which will disrupt the plot and assassinate the leadership of Al Qaeda, including Osama Bin Laden. This will enable us to ponder a history in which the lives of millions of men, women, and children in the Middle East, Africa, and Asia are altered forever.