Jake Epping is a high school English teacher in Maine who accepts a summons over the phone from Al Templeton, the owner of the local diner. He isn't sure what to expect, but it definitely wasn't a wormhole in the back room that leads to the 1958 version of their town. Al's dying request is that Jake use the time tunnel to stop Lee Harvey Oswald from assassinating John F. Kennedy.
Shortly before he learns about the gateway to the past, Jake reads an essay by one of his students about the night in 1958 when his father came home drunk and killed the rest of his family, so preventing that murder becomes his immediate concern. As he bides his time in the 1960s, taking a job as a high school teacher in a small town outside of Dallas, he could be just another stranger who shows up, makes a difference in people's lives and falls in love with a beautiful but emotionally damaged young librarian--except, of course, for the very thing that makes him an outsider in the first place.
King spends a lot of time presenting the late 1950s and early 1960s through the eyes of a 21st-century man-- what songs are playing on the radio, what movies are at the drive-in, and how much cheaper everything is. But he also shows us how much more blatant, and uglier, the racism and sexism were in that era. At first it seems as if King isn't particularly concerned about the complications of time travel; when Jake brings up one of the classic paradoxes--"but what if you went back and killed your own grandfather?"--Al's response is bluntly dismissive: "Why the f*** would you do that?" Later on, though, when Jake is telling his girlfriend about his mission, he starts to describe the butterfly effect, and she mentions she's already heard about it, thanks to Ray Bradbury's "A Sound of Thunder"--a big clue as to how things are going to turn out.
Kennedy surviving Dallas is a staple of alternate history hypotheses, so much so that it's basically become an abstraction. 11/22/63 revitalizes the concept and gives it a renewed emotional power. --Ron Hogan