By Caitriona Murphy
With hooves pounding and adrenaline pumping, 200 horses charge at the enemy ranks. Galloping faster and faster, these magnificent, glossy animals face a wall of German machine guns, yet they continue fearlessly.
Gallant and courageous, the cavalry horses obey their masters' orders, even though every fibre of their beings likely screams at them to run the other way.
It's only when horse after horse is shot down in a hail of machine gun fire that the fear in their eyes becomes visible.
As their comrades writhe in agony on the blood-soaked ground, the few survivors accelerate towards the guns in a desperate bid to escape the hellish war zone.
Steven Spielberg's latest epic movie War Horse is a gut-wrenching account of the horror that cost the lives of hundreds of thousands of horses in World War One.
Killed and maimed by machine guns and heavy artillery, strangled by poisonous gas and ripped apart by barbed wire, the best that any horse could hope for was a quick death. Recreating these atrocities without actually harming any of the horses involved was a major challenge for Spielberg but the American Humane Association awarded War Horse its top rating -- 'Outstanding: No Animals Were Harmed' -- after monitoring 240 horses over 1,100 hours of filming.
So how did Spielberg invoke fear and terror in the horses without actually putting them in danger?
To help him, the director called on South African horse master Bobby Lovgren.
World-renowned trainer Lovgren selected 14 horses to play Joey, the film's equine hero, from foal to mature horse.
While the majority of horses were sourced in Europe, Lovgren also flew one of his own horses in from the United States to play Joey. Thoroughbred Finder had impressed Lovgren so much in Seabiscuit that the horse master bought him from the production company. Finder is also credited in The Legend of Zorro, Mirror Mirror and US TV series Wildfire.
As a specialist 'liberty' horse -- working without any restraints -- Finder was needed for the most dramatic moments in War Horse, including the unforgettable scene in which he gallops through No Man's Land amid heavy crossfire.
"We started working with the horses about three months before filming," explains Lovgren.
"We needed to start teaching them what would be required on set and finding out what each individual horse would be capable of."
This preparatory work involved assessing which horses could cope with the stress of a film set and training the horses for dramatic action scenes. Horses are prey animals with a highly developed flight instinct.
They have evolved into fast thinking, sure-footed, galloping machines whose first reaction to any danger is to run away.
So asking a horse to stand still amidst explosions, gunfire, flashes of light and thunderous noise goes completely against his very nature.
"We used air mortars that would blow up peat moss to recreate explosions," explains Lovgren. "Some horses are comfortable with that but others simply can't cope so we had to find out what each horse's comfort zone was before we went on set," he adds.
Surprisingly, however, the horse trainer's biggest challenges were not the explosive battle scenes but the sequences involving the four foals who played Joey as a youngster.
"They are like working with a little child," he says. "They get tired quickly, so you need a number of doubles with them."
"They're so young that you can't spend as much time training them and getting them ready as you would an adult horse."
While almost all of the scenes in War Horse were shot with real horses, one particularly agonising scene required a robotic substitute.
When Joey gets tangled in barbed wire in No Man's Land, shots of a real horse tangled in barbed wire-effect rubber are interspersed with shots of a full-scale animatronic horse operated by five puppeteers buried in the ground underneath.