Billionaire, software mogul, Adam Pi has everything in life with the exception of positive memories from High School. He begrudging goes to the 20th reunion and has such an amazing time he finds himself wondering "If I knew then what I know now" and offers the entire grad class one year's salary to come back and do one more month of the 12th grade.。2022年地球收到一份来自未来的召唤:30年后的地球遭遇未知物种的攻击,面临灭种危机,为了拯救地球,丹被招募为战士去到未来,支持地球上人类的最后一战。直到亲眼所见,丹才终于知道人类所面临的对手竟是以人为食的残暴怪兽……
关乎人类存亡的最后一场大战拉开帷幕……。