电影以抗美援朝战争第二次战役中的长津湖战役为背景，讲述了在结束了新兴里和下碣隅里的战斗之后，七连战士们又接到了更艰巨的任务……
根据韩战期间真实战事改编。1950年6月25日，北韩挥军越过三八线突袭南韩，三日攻陷汉城（今首尔），战线不断南进。在美军及联合国军支援下，南韩军逆势反击。美军指挥官麦克亚瑟提出代号为「铁铬行动」的仁川登陆计划，该计划急需一支大队的兵力从侧翼阻击扰敌、声东击西，通过长沙里切断北韩军的补给线。 由于任务本身极其艰钜，加上南韩国军当时兵力薄弱，无法抽调足够正规军支援，军方不得不把这项任务交付给772名学生兵执行，这些学生兵平均年龄只有17岁，仅仅接受了两星期的军事训练，在毫无实战经验的情况下投身战场。行军路上固然杀机重重，战友内部也诸多衝突，年少气盛，迸发出各种角力。 仁川登陆战前夕，长沙里登陆任务如期执行，这群徒有一腔热血但战力薄弱的学生们，无可避免地接受命运中最残酷的考验：穿越炮火与海浪，浴血长滩，馀下部队身陷敌军重重围剿，直至弹尽粮绝，挣扎于阵亡与倖存的分界线上… Based on the incredible true story of Jangsari Landing Operation. When North Korea invades South Korea on June 25, 1950, they pushed South Korea and its ally US Army to the southernmost city. U.S. General MacArthur planned Operation Chromite, which would see the joint allied forces to take back a strategic location of Inchon and in order for it to succeed, he needed a small battalion to flank the North Korean army and eliminate their supply line at Jangsari beach. Having lost his family on his retreat away from North Korea before the War, a model student Choi Sung-pil enlists in the army to fight for the South. Ki Ha-ryun is a rebellious youth from the South who volunteers to fight in the war. All of the 772 students and youths are like them who are barely out of school with only 2 weeks of boot camp training. Task force commander Captain Lee Myung-jun knows that it’s a long shot, but he has no choice but to lead them into a crucial mission. Meanwhile, US war correspondent Maggie braves the dangers of the battlefield to report on the war in the frontlines. She feels empathy for the Korean students who must go into battle on behalf of the veteran soldiers for their country, and tries to do what she can on her end to rescue them. With little ammo, scant food supplies and raggedy weapons, can the students successfully carry out their mission and return home safely?
本片以第二次世界大战末期，在意大利登陆的美军攻破德军防线为背景，导演以令人感动的场面把美军从南部攻到北部期间所引发的一些意大利民间故事编成一部有连贯性的社会写实的电影，画面上的真实感，给予人们非常大的冲击，创下了意大利电影的新潮流……大师罗西里尼的战后三部曲的第二部，第一部是《罗马，不设防的城市》，最后一部是《德意志零年》。作为新现实主义的奠基人，罗西里尼几乎不使用剧本，并明确拒绝使用摄影棚、服装、化妆和职业演员。影片由6个小故事组成，背景是二战后期盟军在意大利登陆后攻破德军防线，从南部向北部进攻期间引发的一些民间小故事。罗西里尼在摄影机前重现了美国大兵，游击队员、修道士，妓女，以及普通平民在那个烽火连天的岁月里的真实遭遇，影片穿插了很多真实的战争镜头，令观众感同身受。
