Matt Sunderland gives an unnerving performance as the solitary and angry David Gray.

Matt Sunderland gives an unnerving performance as the solitary and angry David Gray.

Herald rating: * * * * *

Of all the deaths depicted in this film of the 1990 Aramoana massacre, the one that sticks with you the most is the last - that of David Gray, the killer of 13 people who was shot by police 22 hours after he started his rampage in the tiny Otago coastal village.

You are left reeling by both the stark brutality and the telling detail of it all.

In the previous two or so hours you have witnessed the unhinged Gray calmly execute many of his neighbours, the local police sergeant, and anyone who strayed into his sights, young or old.

By rights, you should be punching the air with satisfied relief as Gray - an unnerving performance by Matt Sunderland - writhes his last while the squad which has just dealt to him lift their gas masks to light each other's cigarettes.

Except, Out of the Blue is not that sort of movie.

It's one that makes you dread every sound of gunshot, every movement in the dark, every death. Even the final and fourteenth.

It's a powerful piece of work, made more so by a fierce restraint in its delivery.

Its makers have shaped a narrative from the haphazard events of that day - and a little before in scenes showing the solitary and angry Gray approaching breaking point - but without making this run to a conventional thriller timetable.

Nor is it the police-centric case study as might have been suggested by basing it on Bill O'Brien's book Aramoana: Twenty Two Hours of Terror.

When the violence starts, it is as the title says, out of the blue and all the more devastating for it.

There are a few moments, though, when the storytelling falls away. The frequent shots of the tide at the nearby beach might be a subtle stopwatch on events, but they start feeling like unneeded punctuation.

Similarly, shots of the media pack on the hill above the town showing a TV3 logo on a car - CanWest is one of the film's financial backers - demonstrate that not even a film such as this is immune to product placement.

But those are minor quibbles in a film that otherwise feels like it's done everything that it can to show what it felt like to be caught up in the events of that awful day.

Its portrayals of police and community heroism - especially that of the elderly Helen Dickson - resonate because they come unadorned and played straight in a series of low-key but often gut-wrenching performances.