Dallas, Texas. November 22, 1963. Shots ring out at Dealey Plaza. The president is struck in the head by a rifle bullet. Confusion reigns. 
Special Agent Paul Landis is in the follow-up car directly behind JFK's and is at the president's limo as soon as it stops at Parkland Memorial Hospital. He is inside Trauma Room #1, where the president is pronounced dead. He is on Air Force One with the president's casket on the flight back to Washington, DC; an eyewitness to Lyndon Johnson taking the oath of office. 
What he saw is indelibly imprinted upon his psyche. He writes and files his report. And yet . . . Agent Landis is never called to testify to the Warren Commission. The one person who could have supplied key answers is never asked questions. 
By mid-1964, the nightmares from Dallas remain, and he resigns. It isn't until the fiftieth anniversary that he begins to talk about it, and he reads his first books on the assassination. 
Landis learns about the raging conspiracy theories--and realizes where they all go wrong.