"And ... action!" director Robert Sarkies yells from a film camera platform atop a car.
A battered yellow Laser veers off a beaten track at Cannibal Bay and disappears into a copse of trees.
The whole scene takes about 5 seconds.
"Cut. Check it please," Mr Sarkies says, and clambers down off the car.
It looks like a small army has arrived at the remote Catlins beach to fend off an invasion.
The high-tech set is in striking contrast to the inspiration for the film.
Two Little Boys is based on the 2008 debut novel of Mr Sarkies' younger brother, Duncan, and references the Dunedin brothers' childhood holidays in South Otago.
"It's been lovely, doing this with Duncan. We've been working together, casually, on projects for a few years, but haven't got around to doing anything. So this has been great."
The Sarkies brothers previously collaborated on Scarfies, the 1999 black comedy about Dunedin university students, which became New Zealand's sixth-highest-grossing film.
"Two Little Boys was written for here, but it's been a risk. We've tried to showcase the best tourist spots of the Catlins, but that means lots of exteriors [outside shots], which also means a lot of adjusting the schedule daily, because of the weather."
An average day can see just two to three minutes of the film shot. So, eyes constantly and anxiously scan the threatening sky overhead.
Any on-location shoot had its challenges, executive producer Tim White, of Sydney, said.
"You always prepare the schedule with a good amount of optimism. It's been very unpredictable weather-wise, but no worse than anywhere else in New Zealand," he said.
"It's absolutely amazing here. It has very dramatic skies and a great sense of spectacle, with the tempestuous weather."
Two Little Boys has also benefited from local input, with about 100 residents helping set up the locations.
"The co-operation from locals and downright support has been fantastic," Mr White said.
"We're like a circus that rolls into town and disrupts normal everyday activity, but everyone from the locals to the farmers has been great."
After the Catlins shoot, the crew is this week preparing for eight days of sleeping during the day and working at night.
"The standard day we do is 10 hours, but most people don't work less than 11 or 12 hours. Some people do 16 hours. It may seem glamorous, but eight straight weeks doing those hours and you quickly lose the shimmer," Mr White says.
"You have days that are absolute fun and days that are absolute hell. You try to stay calm and level-headed and supportive. When you're shooting, there's a lot of weight sitting on the shoulders of the director. You have to be prepared and keep a positive frame of mind. You can't let the dread show on your face."
Mr White and Mr Sarkies worked together on the film about the 1990 Aramoana tragedy, Out of the Blue, which became the 10th most successful New Zealand film and won six Qantas Film and Television Awards.
"Out of the Blue was a very difficult film. It changed all of us. It was a profound experience and the hardest film I've ever made," Mr White says.
"Rob is an exceptional film-maker. He's truly one of the best New Zealand's got. He's well-regarded by most prominent film-makers internationally."
One star of Two Little Boys is Wellington actor and musician Bret McKenzie, of Flight of the Conchords.
"I've been having a great time on this film. It's like a big, temporary family," he said.
"This is such a cool project. The script's very dark but, at the same time, hilarious. In a lot of films, people try to make something that's like something else. But, this one is unique. You feel like you're in the middle of something you're not quite in control of, which is very exciting, creatively," he said.
"The weather's been a bit unpredictable, but it's got an amazing vibe here. The Catlins locations have been incredible. Owaka has probably never seen so many people. The locals are so into it."
At the end of the filming this month, Mr McKenzie is heading back to Los Angeles to work on the soundtrack for The Muppet Movie.
"I've got to fix Kermit's vocals."
"We're also hoping to do a Conchords tour of New Zealand this year. I actually met [Flight of the Conchords co-star] Jemaine [Clement] when we were doing Duncan's play Bodyplay at Victoria University in the mid-1990s.
"Duncan also wrote a couple of episodes for the Conchords. So, it's nice - he was working for us and now we're working for him."
The film also features Australian comedian Hamish Blake and Dunedin actor and musician Maaka Pohatu.
Two Little Boys is scheduled for release early next year.
