It's WWI & some British troops have been told to go over the top. In the chaos of fighting, they get lost, stumble upon, & take over what they think is an elaborate German trench.
Standard horror flick. There's your psycho religious zealot that goes insane, your green, lied-about-his-age young private, the xenophobic, foreigner-hating warmonger, the cowards that run FROM safety in numbers to wide open fields of machine guns, razor wire, & death whenever the plot needs, etc.
I know war's supposed to be hell & all, but if all the British tommies maintained this level of discipline, the Austrians alone could've beaten them.
The director appeared to be trying to make some point about war, violence, & evil. We're supposed to believe that a British infantryman wouldn't shoot someone who's already blown away at least one of his fellow soldiers? Come the fuck on. If a known murderer is standing next to your unarmed buddy w\ a rifle, threatening to shoot him, & you happen to have the drop on said murderer w\ YOUR rifle, the correct response is a trigger squeeze. & I'm not even going to go on about how these idiots conveniently split up & go solo at the most inopportune times.