[4] The film was written and directed by Peter Landesman, in his directorial debut, and produced by Playtone's Tom Hanks and Gary Goetzman, Bill Paxton, and Exclusive Media's Nigel Sinclair and Matt Jackson.

[5] The film is based on Vincent Bugliosi's 2008 book Reclaiming History Four Days in November: The Assassination of President John F. Kennedy.

Several people begin their days as regular in Dallas: Dr. Jim Carrico, resident surgeon at Parkland Memorial Hospital, wakes and responds to a call; dressmaker Abraham Zapruder giddily arrives to his offices, telling his employees to come downstairs for the motorcade; FBI agent James Hosty talks with his boss, agent Gordon Shanklin; Robert Oswald, brother of Lee Harvey Oswald, enters his office.

Parkland receives the call that Kennedy is coming in, and Head Trauma Nurse Doris Nelson informs Carrico.

Once the motorcade arrives, agents attempt to move the unconscious Kennedy into the hospital, but Jackie, in a state of shock, won’t allow them to.

Zapruder is hesitant, but Sorrells insists on the matter of national security, and they depart to the news station to develop the film.

Robert arrives at the police headquarters, has an appalling conversation with his mother, Marguerite, and gets indirectly threatened by an officer to change his name and move as far away from the Dallas area as possible.

Shanklin discovers a letter from Lee threatening an attack on the office if the FBI contacts Marina again, and lambasts Hosty for not arresting him then.

Lee is shot on live television by Jack Ruby and is rushed to Parkland, where he is denied entry into Trauma Room One.

In another operating room, after treatment by Carrico, Perry and Nelson, Lee ultimately succumbs to his wounds, to the dismay of Robert and Marguerite.

Three days after the assassination, both Kennedy and Lee have their funerals, and the Parkland staff, Zapruder, the FBI and the Secret Service somberly return to work.

Reviewing the film, he praised its attempt to "capture the desperate efforts made to save Kennedy in the operating room."

He told historyextra, "It shows that the head nurse, Doris Nelson (played by Marcia Gay Harden), had to take a piece of JFK's skull and some brain tissue from Mrs Kennedy [Jackie picked up a piece of her husband's skull at the scene], and that junior doctor, Jim Carrico (played by Zac Efron), had to be told to stop the frenetic but fruitless cardiac massage at one o'clock, when the team declared JFK dead.