When employed as a central conceit in fiction, time travel is often either treated whimsically or as an overarching device for traveling to the Jurassic Era or the far future. But put it in the hands of the master of horror Stephen King and time travel becomes both possible and dangerous.

In “11/22/63: A Novel” (Scribner, New York, 2011, 849 pages), King takes on both American history and one man’s new, second history. It’s a classic case of King taking an utterly ordinary man and dropping him in the most unusual of circumstances, an Everyman meeting the supernatural.

Jake Epping is a high-school English teacher who discovers a hole in time: It allows him to travel back to Sept. 9, 1958—and only that date. You cannot go forward or back; it always returns to that date.

King describes and explains time travel in a manner that is both believable and excruciatingly painful. Epping can go back, but every time he returns to the past, time rearranges itself.

Now he has been left with a mission, to travel back to 1958 and then wait in the past for five years until the titular date of Nov. 22, 1963, when Jake—now known as the real-estate agent George Amberson—must change American history by saving President John F. Kennedy from assassination in Dallas, Texas.

Hanging around in the past is no picnic, though King seems to get all the details right, giving 1958 and its subsequent years a feeling of authenticity. The interesting thing is how King makes staying in the past and waiting an ordeal instead of an amazing thing.

Jake—who spends so much time in the past he feels more like George—has to put up with countless mundane challenges as well as continuing his plan to get to Dallas in time to undo the assassination. He never really asks himself if someone should actually do that.

Like King’s other recent long work, 2009’s “Under the Dome,” there is lingering feeling that the book may be too long—but then one realizes, in this case, that’s precisely the point. Time travel isn’t fun or safe.

King unleashes the real antagonist of “11/22/63,” and it’s not Lee Harvey Oswald. It’s time itself. “Because the past doesn’t want to be changed. It fights back when you try. And the bigger the potential change, the harder it fights.”

It’s amazing how King has connected all his novels in what fans call the King-verse: Not only does the fictional town of Derry, Maine, figure prominently in this book, but there are also references to the events in King’s disturbing 1986 novel “It,” perhaps King’s best, most ambitious and certainly most terrifying work.

This work is no slouch, either. “11/22/63” features King writing lucidly about heavy things and his prose continues to beguile as it terrifies: “For a moment, everything was clear, and when that happens you see that the world is barely there at all. Don’t we all secretly know this? It’s a perfectly balanced mechanism of shouts and echoes pretending to be wheels and cogs, a dreamclock chiming beneath a mystery glass we call life… A universe of horror and loss surrounding a single-lighted stage where mortals dance in defiance of the dark.”

And that is also a pretty accurate description of “11/22/63,” of Stephen King doing that thing he does so well.

Available in hardcover from National Book Store.