From hell: How Brad Pitt and co were put through the wringer on new WWII film, Fury
It features a tank, soldiers and warfare, but Fury isn't just a war movie.
Director David Ayer will tell you that it is actually a drama about a dysfunctional family.
It involves a tank crew who have to accept a new soldier into their unit - the way a family adopts a new member - and the result is a lot of insults, taunting and fighting. At the same time, the team has to be a cohesive unit to stay alive on the front lines of the final days of World War II.
Set in April 1945, Fury, which opens here tomorrow, is told over 24 hours through the eyes of a new recruit, Norman (Logan Lerman).
Trained to type rather than kill, the young soldier is given a brutal introduction to the horrors of war when he is assigned to battle-hardened tank commander Don "Wardaddy" Collier (Brad Pitt).
Wardaddy's "family" includes tank gunner Boyd "Bible" Swan (Shia LaBeouf), loader Grady Travis (Jon Bernthal) and driver Trini Garcia (Michael Pena).
"The movie is a slice of life. It's a portrait of a family in horrible conditions," said Ayer to Indiewire.
"This family just happens to drive a tank around and kill people."
Ayer was very certain he didn't want stereotypical characters of a typical war movie. He wanted ordinary men, but guys with a real bond.
To achieve that, he sent his stars for a hellish six-day boot camp, run by a couple of former Navy Seals.
"It was engineered to break down the individual and build these guys up," said the 46-year-old director to The Wrap.
"They were totally isolated, totally separate, there was no Hollywood stuff going on."
Said Lerman, 22, to GQ: "We'd have to be on watch every night, so there was little sleeping. We all lived in a tent. There's parts of it I probably can't even speak about... "
Bernthal, 38, expressed the same sentiments to Indiewire: "The goal was to get us to start fighting with each other and get us very frustrated because when we couldn't complete these tasks, we wouldn't be able to eat, we wouldn't be able to sleep...
"Once we realised we needed to depend on each other, we actually became a unit."
Ayer, the writer-director behind the critically-acclaimed End Of Watch and writer of the Oscar-winning Training Day, also ordered the five men to go for daily sparring sessions throughout the two-month pre-production period.
"You want to learn something about somebody, get into a fist fight," Ayer told Esquire .
"You'll learn more in five minutes than you will in five weeks of conversations. It's basic."
As his name suggests, Wardaddy serves as the group's father in the movie, dishing out tough love to Norman, forcing the rookie to kill or be killed.
"It's like raising a son in one day," said Pitt, 50, to Total Film.
"In (Wardaddy's) mind, he has to be the patriarch - he has to rule with authority, but his guys need to trust his rule as well."
Ayer told Film Journal: "Logan and Brad have incredible chemistry; you really believe that Brad wants to raise this kid so that he can survive."
He also told Total Film that Pitt, as the eldest of the actors and a father of six, naturally became leader and mentor on and off camera.
At a Fury press conference, Lerman added of Pitt: "He gives a lot and asks for very little. It is incredible to work with him."
LaBeouf's extreme methods of preparation, such as cutting his face, pulling out his tooth and not showering, were not fake publicity stunts, said Ayer. He was doing it for real.
But the director, who will helm DC Comics' planned Suicide Squad movie, told Esquire that the strange behaviour the Transformers star was pulling in public was "an act".
"I saw a lot of what (Shia) was doing as just trying to shed that skin and burn himself in effigy in public so that he can walk out of the ashes and be reborn as this brilliant, freaking capable adult actor," he said.
"Shia has this willingness to commit. He embedded himself with the national guard unit, he shadowed a military chaplain to understand and see first hand how to minister to soldiers and soldiers of faith."
Ayer, who did a tour of duty with the US Navy on a nuclear submarine, had fantasised about making a World War II movie for years and has accumulated a trove of books and memorabilia.
"There are so many stories to tell, but eventually I narrowed in on tank warfare because that's what really won the war," said Ayer to Film Journal.
"Also, there's no classic tank movie."
Ayer had five main tanks for filming. He also had a tank interior built in a makeshift studio that was slightly bigger so it could fit in a camera.
Said Bernthal to Total Film: "The first time we all got in the tank, it was overwhelming.
"By the time we started shooting, we'd been in that thing so much. We'd lived in it, gone to the bathroom in it, cooked in it, slept in it.
"We knew it very, very intimately."
But there were limits.
Once, Pitt and LaBeouf exploded at Scott Eastwood, who plays a sergeant, when the actor spat tobacco in the tank.
It was disrespectful of their home, Pitt explained to GQ. They only held off after realising Eastwood was just immersed in his character as dictated by the script.
Said Pitt to USA Today: "It is amazing how well you get to know each other, five men in a tin can.
"There's something that feels safe about it. It was kind of nice actually, just staying in there. We'd just (talk) and smoke and stink and have a laugh."