介绍：Now the Montecito has been sold to inexperienced young widow-heiress Monica Mancuso, who had it thoroughly renovated, Ed who stayed on as general manager is worried about the top-secret reopening, especially after two recent hold-ups in Indian casinos, but Monica refuses any delay so he can work in new staff. Most old key personnel has left. Danny now heads his late dad's contracting company McCoy Construction, but accepts to return as Ed's right hand, and rehires Mike -who was parking valet- and Sam, whose clients were deserting her, only Ed's daughter refuses. The boys soon find proof the construction crews have been infiltrated as there are at least two officially dead men and computer chips have been planted to cause a blackout one minute after the grand reopening starts, far more sophisticated then in either Indian casino heist.

介绍：埃文（本·斯蒂勒 Ben Stiller 饰）是镇上的一个商店经理，对社区的事务也十分积极然而商店保安却遭遇了意外谋杀，当地警察却无心追查，埃文的生活就此被打乱，他决心自己找出凶手。埃文将目光投向了邻里街坊，并与同样在生活中受挫的鲍勃（文斯·沃恩 Vince Vaughn 饰）、富兰克林（乔纳·希尔 Jonah Hill 饰）和贾马克思（理查德·艾欧阿德 Richard Ayoade 饰）四人组成了邻里联防组，每天在镇上巡逻，当然也借此理由偶尔放纵。在一次驾车巡逻时，他们意外地发现了一个奇怪的金属球，与此同时，镇上也出现了几起神秘死亡事件，联防组在被一只外来生物攻击时制服了它，得知外星人已经入侵小镇，并且通过偷窃人类皮囊来伪装成人，施展攻势。联防组方知行动已经迫在眉睫但却雾里看花，因为小镇上的任何一个人都可能是外星人，然而更可怕的是，外星人的最终目的竟然是毁灭整个地球。得知这一切的联防组能否凭四人之力粉碎外星人的阴谋呢……