In this modern creature feature, a scary internet meme called "Grimcutty" stirs up panic amongst all the parents in town, convinced it's making their kids harm themselves and others. When a real-life version of Grimcutty starts attacking teen Asha Chaudry, her parents believe that she's cutting herself as part of a challenge. With her phone taken away and no one who believes her, Asha has to figure out how to get through to her parents and stop the Grimcutty once and for all.

　　An orphaned teenager forms an unlikely friendship with a detective. Together they investigate her mother's murder, and uncover the supernatural force that proves to be a threat to her family.

大金刚在军警围捕之下，终于从帝国下厦摔下受重伤，十年后，在乔治亚洲特兰大大学医疗研究，有机会再度复活。为此研发人工心脏，准备为她做换心手术，但要量同类的血液。正当大家一筹莫展时，米奇意外地抓到另一只母猿，并卖给政府以便进行手术，艾咪为此手术执刀，不料手术后的大金刚与母原从回原生地，逃开人类的控制，而被军队重重包围，大金刚被炮击而身受重伤。母猿亦在这次攻击受捕，为展开营救母猿、大金刚将再次肆虐人类……

　　“钢铁骑士”曾是美泰一款风行全球的男孩人偶玩具，也曾被拍成电视系列动画片，此次真人电影版的故事是《雷神2：黑暗世界》（Thor: The Dark World）编剧克里斯托弗·约斯特（Christopher Yost）原创的。故事讲述16岁男孩麦克斯（Max McGrath）和母亲居住在一个小镇上，他的科学家父亲当年在他出生后不久就神秘死亡，麦克斯拥有一种他自己都无法控制的超强能量，直到遇到有着先进技术的外星人Steel后，才学会运用它，“钢铁骑士”就此诞生！