In season three, the different perspectives of the alien invasion collide for the first time as the main characters are brought together to work as a team on a critical mission to infiltrate the alien mothership. The ultimate apex aliens have finally emerged, rapidly spreading their deadly tendrils across the planet. It will take all heroes working together, using their experience and expertise, to save the species. New relationships are formed, old relationships are challenged and even shattered, as an international cast of characters must become a team before it's too late.

詹妮弗·劳伦斯准备执导一部叫《Project Delirium》的电影，改编自一篇60年代心理战的文章，一场化学实验彻底失控的故事。她所说的文章是2012年刊登于纽约客的《Operation Delirium》，叙述冷战时期的美国政府，在近5000名军人上所施行的生化武器实验，结果彻底失控的故事。