Prologue:A trio of German soldiers working down in the tunnel system underneath the bunker encounter a mine shaft. While performing construction the lights begin to flicker and they hear movement, causing them to aim their rifles at the shaft and then to run away frantically.Main Story:In late 1944, the remnants of a platoon of German Panzergrenadiers from the Großdeutschland Division are caught in an ambush by American troops. In their retreat, during which Engels is killed, they find a bunker, manned by an old man (John Carlisle) and a young boy (Andrew-Lee Potts). Left to defend the bunker and presuming themselves surrounded by the US forces which ambushed them, they are left by Area Command "to wait until relieved". Schenke confronts Heydrich about why the group didn't counter attack the Americans, claiming that there couldn't have been too many of them. Mirus expands on the history of the area, revealing that victims of the Black Plague were massacred on the orders of a stranger who influenced the townspeople to turn against one another. Low on ammunition, the men are haunted by bad dreams, memories, and the feeling that something about the area just isn't right.As the night proceeds, strange tunnels are found beneath the bunker and the situation in the bunker becomes increasingly tense. Schenke wants to explore the tunnels, but Lt. Krupp orders against it on the rational that they are supposed to hold the bunker, not go exploring. Later, Mirus sneaks down into the tunnels. Curious, Kruezmann, one of the soldiers who had been suffering from the dreams, follows. Soon others discover them gone, and convinced that they deserted, Lt. Krupp orders a pursuit. Interrogation of Neumann reveals that Mirus had been wandering off into the tunnels for several weeks. Neumann also reveals that Mirus treats the tunnels as his own personal property, and that it was as if there was something down there that Mirus didn't want Neumann to know about. Baumann discovers a set of plans for the complex while Ebert discovers the same danger sign that was seen in the movie's prologue. He continues walking and comes to the same mine shaft, were he hears movement and sees a pile of sand fall nearly on top of him. Terrified, he begins backing up but is suddenly stabbed from behind. Ebert crawls over to the wall, his assailant apparently having left promptly after stabbing him and lets out a yell of agony. Meanwhile, Baumann, presumably hearing something, packs up the papers and begins looking around for the cause. Suddenly, his flashlight goes dead. Meanwhile, Ebert is still dying from the stab wound. Suddenly, a silhouetted figure who looks like Kreutzmann begins to walk up. Meanwhile, Baumann has successfully lit a match to replace his dead flashlight. The wind continues to blow and his match nearly goes out. The already frightened scout sees figures walking towards him and aims his weapon, but is stopped before he ends up shooting any of his fellow soldiers. However, when Lt. Krupp tries the flashlight, it turns on easily.Baumann then hypotheses that the Americans are in the tunnels, which is backed up by Sergeant Heydrich, who refers to the entrance on the far side of the hill that Neumann mentioned earlier. The group then hears movement, which turned out to be Mirus. Sergeant Heydrich then scornfully tells Baumann "there's your Americans." The soldiers then turn on an rusty old generator, causing a series of lights to turn on down in the tunnels. Lt. Krupp asks Mirus what's going on, but Mirus is evasive. Before the questioning can go any further, the men hear machine gun fire coming from the bunker. However when the men arrive(except for Mirus who is told to watch the tunnels) it appears that Neumann, Franke and Schenke had been firing at nothing or if they had been that that the Americans had left long before the firing stopped. Lt. Krupp attempts to call headquarters but the phone lines are dead.Convinced that the enemy has worked their way into the tunnels, a terrible game of cat and mouse develops. Stalked by shadowy figures, it becomes increasingly unclear where their fantasies end and the danger begins. The Lt. agrees to send an expedition to secure the back entrance to the tunnels, but under the condition that if too much resistance is encountered they return. Mirus and Neumann are left behind in the bunker, while the remaining men split up into a group of two and a group of three. Before leaving Schenke gives a Heil Hitler salute which none of the men in the other group return. Back in the bunker Neumann keeps standing guard while Mirus scorns the whole idea of trying to fight anymore. Her then claims that his son Werner, who died in Normandy still talks to him and told him something about the tunnels, much to Neumann's disbelief. Meanwhile, down in the tunnels, Schenke and Lt. Krupp force their way into an ammo storage room, but it's all artillery ammo. The men move on, but plan to come back and deal with it later. They make it to the doors and find that they are still sealed, but Schenke hypothesizes that there's another way in. He continues searching despite Lt. Krupp yelling at him to stop and they soon come across Ebert's body. Meanwhile, the other group comes across the same mine shaft seen in the prologue, and Heydrich and Franke go to check it out while Baumann covers them. While investigating the shaft they come across a mass grave. They then hear murmuring and come across Kreutzmann, who's catonic, screaming no over and over. Kreutzmann begins babbling about someone or someones being back. Heydrich and Franke hear a women's voice and try and get Kreutzmann out of there, but Kreutzmann, whose stuck in a flashback, is fighting them. He breaks away from Heydrich and Franke, knocks Baumann out cold when Baumann walks over to the mouth of the shaft to see what's going on and runs off. He then hallucinates he's seeing one soldier with his throat ripped out while two others take pictures. He runs off again. Meanwhile, Lt. Krupp and Schenke are in a corridor when the lights begin to flicker out. They hear movement and look, only to spin around a second later when they hear movement behind them and see a lamp swinging from side to side. They slowly back down the corridor and make it to the back door, so to speak, of the tunnel complex. They hear loud banging as something tries to break into the tunnels. Kreutzmann comes rushing up the tunnel screaming, causing Schenke and Lt. Kruppe to open fire, killing him. However, Lt. Krupp is buried under a pile of wooden beams which fell when the men opened fire. Schenke checks the body of the man they killed, sees its Kreutzmann, and begins laughing hysterically. Meanwhile, Neumann, hearing the shooting, ventures down into the tunnels despite Mirus telling him not to. Mirus meanwhile, panics and runs away after seeing a shadowy figure. He then hears pounding on each consecutive set of doors he closes after him, so he thinks something is chasing him(spoiler alert---the banging is actually Heydrich, Baumann and Franke). Mirus leaves the bunker and falls outside into the barbed wire. He sees another dark figure approaching and in his panic to get away becomes more and more tangled in the barbed wire. Meanwhile Neumann, who is searching through the tunnels, is caught by Schenke, who puts a knife to his neck. Neumann soon gets Schenke, whose becoming more and more paranoid, to trust him however. The two of them return to the artillery ammo room Schenke discovered with Lt. Krupp and booby trap the room to prevent the ammo from falling into the hands of the Americans, Schenke is sure are stalking through the tunnels. Heydrich, Baumann and Franke decide to blow the bunker door with a stick grenade and fight their way out. Meanwhile, Schenke and Neumann hear the explosion and think that the Americans had set off an booby trap.Schenke lights a fuse to destroy the artillery ammo and the two of them move out. Meanwhile, Heydrich, Baumann and Franke's plan to blast the door open fails so they go looking for another entrance. They run straight into Schenke and Neumann, who thinking that the three of them are Americans, open fire. After a short fire fight in which Heydrich, Franke and Baumann use up their remaining STG-44 ammo they withdraw. Franke finally cracks and offers to surrender, but it turns out that instead of Americans Schenke is the one in the corridor. He looks rather deranged at this point. Neumann comes up and aims his K98K rifle at Heydrich, Baumann and Franke as Schenke basically announces his plan to execute the three of them. When Neumann refuses to execute the three of them Schneke pulls out his Luger and executes Franke. He then puts the gun to Neumann's head and threatens to kill him. Neumann is about to pull the trigger when the explosives go off, knocking everybody down. Heydrich, Baumann and Neumann make a run for it while Schenke wildly fires his pistol after them. The three men race through the tunnels but the main exit is blocked off by wreckage. Heydrich pulls Neumann into the mine shaft in order to get away, but Baumann, whose now holding the rifle, stays behind and shoots at the helmeted figure approaching. To his amazement and terror the bullets seem to do nothing. He then begins hallucinating and fires a third shot before Heydrich pulls him away. Soon Schenke arrives, but the others have already erected a barricade over the mine shaft entrance. The men stumble across the mass grave again and then Schenke appears, destroying the barricade. Heydrich shoots Schenke in the chest and Schenke suddenly bursts into flames, screaming and reeling away. The three men begin whacking at the mass grave wall with entrenching tools which break ground. Neumann breaks out and Heydrich is about to follow him when he's stabbed in the back by Schenke, who despite bursting into flames seems to have put them out, however he's badly burned. Baumann launches himself at Schenke and the two begin a fight, which seems even for a while until suddenly Schenke throws Baumann back. Heydrich suddenly intervenes only to get run through by Schenke. However, the distraction gives Baumann time to get away. After a bizarre scene in which Baumann breaks through a layer of soil made up of bones which seems to try and suck him back into the earth, he's saved by Neumann who pulls him out. Baumann then rolls over and hurls a potato masher or stick grenade down into the hole, which lands next to the gravely injured Schenke. Several seconds before it's explodes Schenke sees several silhouetted figures standing nearby. The movie then cuts to Neman and Baumann running away as the grenade explodes behind them, presumably killing Schenke. Neumann then checks out the bunker from the rear, and comes back to tell the wounded Baumann that its safe. Baumann gives Neumann a handkerchief and tells him to go surrender. Neumann wants to stay but Baumann point blank refuses, telling Neumann to go on, leave. Neumann agrees to leave and on his way down the road finds Mirus' body tangled up in the barbed wire. He then sees American soldiers emerging from the woods and waves his handkerchief to get their attention. The film then cuts back to Baumann's memories which show the squad advancing across a sunny field only to find a bunch of deserters about to be executed. An officer hustles over Baumann to participate in the firing squad. One of the deserters is seen praying, and Baumann misses his first shot before shooting the man twice to finish him off. Quickly the firing squad moves in, with one soldier taking pictures with his camera and an officer finishing off the only wounded with a pistol. One member of the firing squad is seen striking a pose while the picture taking soldier snaps another shot. Baumann snaps out of remembering and staggers off towards the Americans.- Source: Wikipedia
Output: Question: Why did Heydrich, Franke and Baumann withdraw from the firefight?, Answer: They ran out of ammo.