Dateline: Austin, Texas —  IT CAME. AND IT WENT. In flash, it seemed.

“SXSW Interactive”, or the digital tech part of that annual multimedia extravaganza called the South by SouthWest festivals is now over – and it was on steroids this year, opening with the first-ever appearance by a sitting US President.   He provided, by the way, a text-book Obamite keynote address, sharp and deeply engaged while calmly de-fraying the fray of bitter controversy.

SXSW Film continues on, while SXSW Music also gears up today – with its own splashy kickstart from the White House … Michelle Obama, here to beat her own resonant drum for women’s and girls’ education.

In that happily continuing Film section, selected from something like 3,000 entries, the narrative drama contender that has hit me the hardest has been Demolition, directed by Jean-Marc Vallee (who made The Dallas Buyers’ Club ) and screenwritten by Bryan Sipe.

It’s the story of a (rich, of course) investment banker played by Jake Gyllenhaal (top left), who strikingly early in the movie loses his wife – suddenly, violently, sickeningly – in a car wreck.

The banker – already pretty benumbed by his daily lucre-amassing work – is pitched into even further numbness, bordering on emotional catatonia. He goes back to the office after his wife’s death astonishingly early even for the driven world he inhabits, and horrifies colleagues with his evidently callous concentration on the clever deals at hand, plus some other irrelevancies.

Sipe’s screenplay is spicily peppered with dialogue whose comic darts also seem totally at odds with the situation’s somberness. But it helps to sustain the involved, edge-of-the-seat attentiveness that the story demands.

The career-high level of Gyllenhaal’s performance is more than matched by Naomi Watts (top right), who gets subtler and stronger every time I see her, and by the ever-powerful and this time emotionally wringing Chris Cooper.

Much of the narrative flow employs voice-over (an industry-wide choice both criticized in the Festival’s many discussion sessions, and praised for when it really works), Here the choice could be easily counted as part of Vallee’s overall effort to keep the audience on its back foot, as the voice-over repeatedly toggles us between comedy and tragedy. I feel, though, that the particular text employed – Gyllenhall conducting his continuing correspondence with a vending-machine company’s “Customer Service Department” – loses its own arch footing at times, especially during the film’s earlier stages, and we are made naggingly aware of the device’s artifice.

But I did walk out of the movie by the end fully swept away.

And that blunt one-word title, Demolition? Well it’s obvious who is the wreck here. And we do get to see lots of stuff come crashing down. Mercifully though, and with gratifying filmic creativity, we see much being built up afresh.