洛基（迈克尔·特瑞威诺 Michael Trevino 饰）、小马驹（麦克斯·艾略特·斯莱德 Max Elliott Slade 饰）和丹丹（Chad Power 饰）是情同手足的三兄弟，他们的祖父田中（黄自强 饰）曾是身怀绝技的忍者，趁着三兄弟前来度假，教授了他们几套独门绝技。 三兄弟的父亲山姆（Alan McRae 饰）是FBI的探员，正在追捕恶名远扬的军火走私商人施耐德（Rand Kingsley 饰），没想到却遭到了后者派出的忍者兵团的暗算。为了完成一笔交易，施耐德绑架了三兄弟，以他们的性命相要挟，使得山姆不敢轻举妄动。田中和施耐德曾经有过一段不太愉快的过去，如今外孙们生命危在旦夕，田中毫不犹豫的重出江湖，直捣施耐德的大本营，一场恶战即将拉开序幕。
Plot Summary:Each year, three brothers, Samuel, Jeffrey and Michael Douglas visit their grandfather, Mori Tanaka, for the summer. Mori is highly skilled in ninjutsu, and for years he has trained the boys in his techniques. After an organized crime ring proves to be too much for the F.B.I., it's time for the three ninja brothers! Using their martial artistry, they team up to battle the crime ring and outwit some very persistent kidnappers!
