Measured by the usually warm standards of the Toronto Film Festival’s audience response meter, the world premiere of Oliver Stone’s “Snowden” received an apparently cool reception. But, as with espionage, there was almost certainly more going on under the surface than appeared at first sight, Variety said.

The film received repeated smatterings of polite applause at the packed Roy Thomson Hall as the end credits rolled shortly after midnight. Stone and members of the production crew took a single bow from a spotlighted mezzanine-level box.

It seems very possible that the audience was chilled by what they had just witnessed, rather than cold towards the movie.

Overheard corridor talk was very much about the plight of NSA operative turned whistleblower Edward Snowden, who now lives in an unwanted exile in Moscow. Other debriefing chatter took the “I remember when” personal form with folks exchanging uncomfortable memories of when they were first made to take notice of the global snooping threat that Snowden and “Snowden” deftly uncover.

The two-hour film delivers a strong cocktail of excitement, technical detail, and personal insight, as it mixes up archival news footage with reconstructions. (Spoiler alerts from here on.)

The testy act of downloading the illegally gathered intelligence to a trio of investigative journalists has already been seen on the big screen in Laura Poitras’ equally scary 2014 documentary “Citizenfour.” Stone carefully replicates Snowden’s whistleblowing days holed up in a cramped Hong Kong hotel.

The largest portions of the film, however, are related to Snowden’s backstory as it relates to his recruitment by the CIA, his training, and geeky brilliance in devising spy software programs which he naively thought might be put to a simple defined purpose. And also to Snowden’s bumpy love life with his far more outgoing girlfriend Lindsay, who manages to combine photography with exotic dancing as her chosen career paths, and happily leaks her life onto social media.

Together, the twin tracks demonstrate Snowden’s growing unease with the ‘intelligence community,’ his gnawing belief that politicians were lying to the American public, and build-up to the moment that he became the worm that turned.

Another indication that the Toronto audience was watching attentively, rather than frozen rigid, came moments before the end when, there was spontaneous applause for a neat piece of film-making craft. In a smooth reveal, Stone swaps out actor Joseph Gordon-Levitt replacing him with footage of the real Edward Snowden, letting the conscientious objector speak for himself, if only for a few lines.