"22 July" is not about Anders Behring Breivik's murder spree on that day in Norway in 2011: "It's a film about what happened afterwards," director Paul Greengrass said on Wednesday ahead of the film's world premiere.
But Greengrass, renowned for visceral action sequences in films such as hostage drama "Captain Phillips" and the Jason Bourne series, does not shy away from putting the terror explicitly on screen.
The movie opens with Breivik using food blenders and a cement mixer to make the explosives for a bomb he detonates in the government district of Oslo, killing eight people, a scene that is inter-cut with fresh-faced youngsters arriving at an island summer camp where he will massacre 69 of them.
White-nationalist Breivik, played by Anders Danielsen Lie, arrives on Utoeya disguised as a police officer sent to protect the children, before calmly stalking across the island shooting as many as he can.
In real life, the shooting spree lasted more than an hour. In "22 July" it is over in a few excruciating minutes.
Greengrass said survivors and the bereaved families had asked him not to "sanitize" the violence, but also to treat the tragedy with respect.
"There are only a few fleeting moments of graphic violence," he told a news conference.
"By far the preponderance of that sequence is suggested violence. Now, of course, it has the power to shock and disturb, but I think a fair viewer would say that it was handled with restraint."
FIGHTING FOR DEMOCRACY
The film focuses on teenager Viljar Hanssen, excited to be at the annual summer camp organized by a youth group affiliated to the Norwegian Labour Party, where the kids play sport, sing around camp fires and talk politics.
Breivik finds Viljar cowering with others on a cliff ledge and opens fire. The boy somehow survives multiple gunshot wounds, including one to his brain, and the film follows the true story of his recovery and decision to confront his attacker in court.
Greengrass said he had planned to make a film about the migration crisis but turned to the Breivik story instead as it was a microcosm of the issues he wanted to address, and hopes the movie will inspire young people to confront the rise of nationalist and racist ideology.
"You have the story of how Norway fought for her democracy how her politicians, how her legal system and how ordinary people caught up in the middle of these events fought for democracy against this threat. And every moment since then I think that threat has become more pronounced," he said.
While stressing that he was making no direct comparison between mass-murderer Breivik and alt-right campaigners such as Steve Bannon, the subject of a documentary also being shown at Venice, Greengrass said they shared a similar rhetoric.
"What was extraordinary to me was that the world view that (Breivik) propagated, the rhetoric that he deployed, the arguments that he used, that in 2011 would have been considered outré, are now pretty much mainstream dialogue."
"22 July" is one of 21 films competing for the Golden Lion that will be awarded at the Venice Film Festival on Saturday.