Four years after his 2008 First World War epic "Passchendaele" hit the silver screen, the Canadian actor, writer and director will be using some of his own experiences overseas for a new film set in Afghanistan called "Hyena Road."
As Canada's combat mission was winding down, Gross spent two weeks at the forward operating base at Sperwan Ghar, 30 kilometres from Kandahar City.
"Outside the wire" is an expression soldiers use to describe venturing outside relatively safe and fortified bases, like the one at Kandahar Airfield where Canadian troops spent much of their mission. Gross actually put on the full battle gear and joined in a number of foot patrols.
"It's amazing. I've never been so conscious of my feet (than) the first time I went out. It's interesting about the different levels of 'outside the wire,'" Gross told The Canadian Press at an interview in Banff this week.
"You can have a certain level of danger even in an (observation post), which is manned, but when you're outside the base the phrase 'outside the wire' is something quite a bit different from whatever you thought it meant."
Gross has finished a script largely based on interviews he did with soldiers about their jobs — the film's entire opening sequence, in fact, was based on the experiences of one master sniper.
"It's to do with a sniper (and) an intelligence officer — both Canadian soldiers and a legendary mujahedeen fighter and how their paths converge with unpredictable consequences," he said.
"Because that actually as far as I can see is at the centre of counter-insurgency."
Gross will play the role of the intelligence officer and he is holding out for Omar Sharif as the mujahed because "he looks completely wild now."
The film got its title from a route built in part by Canadian and American troops to link the western edge of Panjwaii to the main highway to Kandahar City.
"I filmed about 60 hours of stuff all in Kandahar province," said the 53-year-old.
"I'm going to use all that inside the movie but the story actually emerged from the time over there I spent talking with soldiers."
Gross said filming is scheduled to begin in southern Jordan in January, once the heat dies down a bit. He said the terrain is similar to Kandahar but is without grapefields and grape-drying huts, which will have to be built.
And he added that "Hyena Road" will have a very different feel to it than "Passchendaele."
"It's kind of the antithesis of 'Passchendaele,' which has a big romantic sweep and it was such an enormous war," Gross said.
"Afghanistan is quite a small war in both its length and cost. It's like the other side of it. It has a gritty, gritty documentary style feel to it and all the stories come directly out of conversations."
Gross said he finds it fascinating that Canadians don't feel comfortable with the idea of military special operations, special forces and snipers because it feels too premeditated.
He said the public seems more comfortable with taking the high ground and the premise of winning the "hearts and minds" of the Afghan people.
"The rules in Afghanistan are that everybody knows them. If you pick up an RPG (rocket propelled grenade) or an AK-47, you're in trouble. It's black and white. There's very little grey area whereas 'hearts and minds' is a moral swamp," he said.
Gross isn't referring to "Hyena Road" as a war movie. He said it's meant to offer a snapshot of a moment in time.
"The Canadian Forces represent our country with amazing dignity and honour and we should be very proud of them, despite what you may think about the virtue or lack thereof (in) any given mission. Our soldiers represent us very well."