“What is a Snowden?” she asked. The lady was in her 70s, eager to see a good movie on a rainy day. She stood in the lobby of the movie theater where I had just reviewed Oliver Stone’s “Snowden,” the story of one Edward Snowden, former NSA and CIA analyst, who stepped out of the cloak and dagger shadows and ran off with a basket of secrets.

“It’s a spy story,” I answered.

“Oh, no thanks,” she replied and walked off.

Of course, it’s much more than that, much, much more.

Here, then is the amazing, disturbing and thrilling story of Edward Snowden, what he did, and the earth shaking consequences of his actions, a shaking that has yet to cease and may impact the coming election.

Here is what I learned from refreshing myself with the web of news reports out of the past:

Edward, a high school dropout, was nevertheless the ultimate geek. After a brief stint in the paratroops where he broke both legs, Snowden went on with sheer grit and guts to become a systems administrator for the CIA and NSA, and then was recruited to work for a private intelligence outfit named Dell. Once inside this world, he found himself at a couple of distant posts in Japan and Hawaii in 2013, working as a systems analyst.

In Oliver Stone’s riveting film, we get to see, walk inside and sneak out of the American spy world’s huge secret surveillance cavern in Hawaii.

It was considered impregnable; they didn’t know Edward.

Here, a team of young men and women, the best and the brightest like Snowden, played with computers in a Silicon Valley environment unlike anything Steve Jobs could have dreamed of.

They played games and invented little surveillance dirty tricks.

It was there that Edward discovered just how far down Alice’s rabbit hole he had fallen, and how filled with Mad Hatters and Cheshire Cats it truly was.

It was there he learned the width and breadth of the NSA and CIA’s surveillance system, and how they collected daily from YouTube addresses and phone numbers of people like you. Yes, YouTube. That camera eye above your laptop screen? They can turn that on, and you become the star of their show. I’m not kidding.

It gets better, deeper, darker, more frightening, as we follow Edward Snowden down the hole.

Edward finds that his bosses were not only spying on foreign countries, friends and enemies abroad, but American citizens as well, and that they were monitoring his girlfriend Lindsay Mills (Shailene Woodley) so they could more closely watch him. This is when his conscience and moral center came to a boiling point. This is when Edward Snowden found a whistle to blow and put it to his lips.

Writer Kieran Fitzgerald and the legendary fire-breathing director Oliver Stone (“JFK,” ” Platoon”) have from scene one created a terrifying, intense and masterful thriller. The team locked in the hotel room stops breathing when a hotel phone rings, when an envelope is slipped under the door. The mirrored halls are always empty, soundless.

The amazing trick here is, one needs know nothing about Snowden to enjoy this film. Stone’s Edward Snowden becomes “everyman,” and “Snowden” becomes a pure spy thriller. It could have been about anybody. It’s truth that plays like fiction, New York Times writing that plays like John Le Carre.

Joseph Gordon-Levitt (“The Walk,” “The Dark Knight Rises”) is a superb Snowden and carries the film in his hands throughout. It’s his best film so far and guaranteed a nomination.

Zachary Quinto as Glenn Greenwald, Melissa Leo as Laura Poitras and Tom Wilkinson, all well known award-winning professionals, play the team that lived with Snowden in his barricaded Hong Kong hotel room. Their tension, anxiety and courage add flesh to the blood of their story.

Rhys Ifans (Mycroft Holmes on TV’s “Elementary”) brings a whispery deathly chill to his scenes as Corbin O’Brian, the ghostly head (think James Jesus Angelton) of “Dell.”

Shailene Woodley (George Clooney’s daughter in “The Descendants”) as Snowden’s suffering but patient girlfriend, who by the way lives in Russia with him now, hits all the right notes. A special guest makes an appearance, and it’s not Julia Roberts.

J.P. Devine is a former stage and screen actor and author of “Will Write For Food”.