该片是环球动作片《小人物》的续集，讲述了哈奇在与俄罗斯黑帮交手4年后，很享受这份激烈的打斗“工作”，但他与家人关系日益疏远。于是，他决定带着家人去旅游小镇度假。然而，一次与小镇恶霸的冲突后，让全家人卷入了一场纷争之中的故事。

1990年，一艘巨大的飞船出现在地球上空，人们惶恐不安，却又分外好奇。经过一段时间紧张的等待，外星飞船始终没有动静。人类终于小心翼翼靠近它，强行走进舱内，结果发现了不计其数的外星人。他们形容丑陋，宛如虾子，而且健康状况极差，虚弱无力。原来这是一群来自外星的难民，他们最终被地球人接纳，并隔离在南非约翰内斯堡的一片区域内生活，此地名为“第九区”。经过长达20年的繁衍，外星难民的数量扩张至180万之多，且和周边人类的矛盾冲突不断，越来越多的人类呼吁将“大虾”赶出地球。
　　MNU（列国同盟组织）经过磋商，决定将外星难民迁移到更为偏远的区域。MNU外星事务部门的特工威库斯（Sharlto Copley 饰）专门负责搬迁工作。威库斯在动员过程中傲慢随意，与当地居民冲突频频。最终，他为自己的行为付出代价，外星人的神秘流体

The film, by director Christopher Leone, follows a day in the life of Randy and Mike, two overworked, underpaid, and nearly burnt-out paramedics. One is so burnt out by the job that he is forcing himself to resign, though he first must embark on one last 24-hour shift to train his replacement. Everything that could happen on the job, from the mundane to the extreme, then happen...

　　A scientist performing illegal stem cell research is trying to find a cure for cancer. After the transfer of shark cells is made into a human test subject, the ill man gets well again and it looks like the treatment was a success. But the experiment goes wrong, and the man transforms into monster: half-shark & half-human. But the scientist knows how to use this to his advantage. He has invited some of his old pals to the island and is hoping to take revenge on them with his new creature. But do they have any tricks up their sleeve?