John Varley's time travel story "Millennium" which came out both as this film and as a full length novel with the same title in the 1980's is one of his best pieces of writing.
Varley's initial concept was first published as the short story "Air Raid" and he was commissioned to write the screenplay for this film version: at about the same time he published an extended version of the short story, lining up with the film but including some rather broader themes and more detail in several areas, as the novel "Millennium."
If you have read the novel and are wondering whether the DVD measures up, it was not practical for the film makers to get the full scope of the novel into this film adaptation, but they did a pretty good job. Most of the political comments about air safety in the book, particularly those about the battle between Ronald Reagan and the air traffic controllers did not make it into this film, and neither did the quasi-religious aspects of the book. But most of the guts of the story did.
In particular, the film is faithful to the plot and tone of the novel, including both the central romance and some of the most gripping action scenes. Both the book and the film capture brilliantly some of the most memorable scenes in the story, and incorporate one or two quite funny moments, none of which I can begin to describe without spoiling the plot.
Kris Kristofferson is excellent as an air crash investigator, who discovers some unusual anomalies in the wreck of an aircraft. Cheryl Ladd is equally brilliant as the mysterious woman who sleeps with him and then disappears. As the story continues we learn more about the investigator's past, and why the mysterious woman reminds him so much of someone he remembers from his childhood.
I can recommend both the book and the film. If you might want to experience both I don't think it makes any difference in what order you do it. If you want to read the original short story "Air Raid" it is included in the collection "The Persistence of Vision" which I understand was also published as "In the Halls of the Martian Kings."
DVD extras are a little basic: short filmographies on Kristofferson, Ladd, and one or two other people, a short synopsis of what the producer was trying to do, and an alternative ending, which differs only in the backdrop to the Winston Churchill quote which provides the very last words of the film.
Varley made a joke about this book (and film) in one of his much more recent novels, "Mammoth" which I can also highly recommend.