A conflict develops between a troubled Vietnam veteran and the sister he lives with when she becomes involved romantically with the army buddy who reminds him of the tragic battle they both survived. 水手刀：用三个人的张力支撑。关于水手刀。 退伍美国大兵David （High School） Flannigan回到家乡跟妹妹Martha Flannigan一起生活，并当汽车修理员维生。他的整副心思仍留在越南战争的记忆中，因此变得沉默自闭。老战友Joseph9(Jacknife) Megessey来探望他，跟David的妹妹擦出了爱情火花，与此同时，则尽让David勇敢面对隐藏在脑海深处的战争创伤，好让他早日解除心结恢复正常。
