沃尔夫和谢莉尔结婚二十载，感情依旧十分甜蜜。实际上，他们这个庞大的家族里一直隐藏了一个秘密，那就是他们是一个专注于行窃的“犯罪世家”。常在河边走哪有不湿鞋，终于，沃尔夫被警探迈克（卡洛斯·博纳德 Carlos Bernard 饰）捉住了，谢莉尔本以为这不过是一次小小的失误，只需要接收一点小小的惩罚，哪知道沃尔夫有可能将要面临的是为期五年的牢狱之灾。
谢莉尔的家庭实际上充满了漏洞，儿子卡尔（帕特里克·福伦格 Patrick Flueger 饰）和黑帮勾结实行抢劫计划，却因此遭到了黑帮的追杀。女儿希瑟误入歧途被人拍下裸照勒索要挟。就连最正直的罗根，也隐藏着他黑暗的一面。

Season four continues the incredible story of the 4400. Old adversaries become new allies, and family ties are strained to the breaking point in the battle over promicin. Can the 4400 lead mankind into a new world, or will the forces working against them spell the end for their kind?

"The 4400" tells the stories of 4,400 alien abductees after they are returned to earth. In the words of the executive producers, these are stories of people dealing with traumatic changes, driven by the mystery of what happened and why. Some of them have been affected in mysterious ways, and some will have certain abilities, both good and bad, so part of the drama will be watching them adjust to these changes within themselves.
The series kicks off with a ball of light sailing toward Earth, but rather than the expected catastrophic event, thousands of returned abductees are left with no memory of their otherworldly experiences. Each has been gone anywhere from a few months to several decades but hasn't aged a day.
在海滩事件——4400人被未来世界的人带走又送回来，披露后一年，世界发生了巨大的变化。经过一段紧张的医疗观测后，Tom回到了国家技术援助中心，由于能力有限，被派做文书工作。他最终保护了儿子，使其免受一个类似的政府研究，而且也为有希望重新过上正常的生活而激动。在事业方面，他也渴望再次同Diana合作，重新回到这个领域。Diana，在同一连串无能的搭档合作之后，最终找到毁掉公文让Tom重回岗位的办法，在此期间，她还正式收养了Maia。
其间，Richard，Lily，和他们的孩子——一个六个月大，不同寻常的孩子，仍然住在远离Jordan Collier的山间小屋里，过着粗茶淡饭的日子。Collier已经关掉了Arcadia Estates ，还有他的住宅，为这4400人建起了避难所，同时准备开“4400人中心”，在这儿，其他人可以深入到这4400人当中，自己去发掘4400人（的奥秘）。Collier在接触Lily的腹部之后，出现了有害的反应，Shawn治愈了他，之后他们就发展出亲密的父子关系。Collier成了Shawn的监护人，并利用他医治4400人中心的重要赞助人。
世人对4400人甚感好奇，于是关于他们的神秘能力的流言四处传播，公众态度分为两种，一种是包容他们，一种是畏惧他们。当4400人努力重新开始他们“被打断的生活”时，每个人都会在即将发生的事件中扮演关键角色…那些决定人类命运的事件。

Over one year ago, thousands of missing people returned. Slowly, they begin to manifest strange powers - to heal and to destroy, to alter the present and to perceive the future. As it becomes clear that their gifts could reshape the world, the struggle for control begins. Who will decide the fate of humanity?

During the past century, thousands of people have gone missing. When 4400 of them return all at once unharmed and looking the same as when they disappeared, the government investigates, unsure of how this can be possible. What the government does not know is that the presence of these 4400 will change the human race in many unexpected ways.