In the final season, Jason Hayes struggles to balance his warrior’s existence with the responsibilities of single fatherhood. Ray Perry, his trusted second in command, questions whether he will be able to leave the battlefield behind as his retirement nears. Dedicated door-kicker Sonny Quinn battles against changing tides as Jason and Ray’s shifting focus means that other teammates must shoulder more responsibility. Both Omar Hamza and Drew Franklin find diving into work an effective way to distance themselves from their past traumas. Vital to mission success is Lieutenant Lisa Davis, a no-nonsense officer who ushers the team into a new era of warfare against powerful rivals for supremacy on the world stage. Ripped away from their loved ones at a moment’s notice to be deployed across the globe, Bravo team remains dedicated to their duties. Even in the face of overwhelming odds, they know this is the price to keep the families they left behind safe.

　　在发现船长莎拉·兰斯(凯蒂·洛茨 Caity Lotz 饰)被外星人绑架后，剩余的传奇们必须设法将其拯救出来，于是他们找到了一名据说曾经遭受过外星人实验的埃斯佩兰萨·"斯普纳"·克鲁兹(利塞斯·查维斯 Lisseth Chavez 饰)，来试图找寻莎拉的具体位置。
　　而被绑走的莎拉，在外星飞船上发现了盖瑞(亚当·切赫曼 Adam Tsekhman 饰)的真实身份其实是一名外星人后，与其一起坠落到了一个未知的星球之上。