L is recruited to save humanity from a deadly virus that wiped out a whole Thai village and his friend F. His opponents are K and a twisted environmental group who want to "cleanse" the world of it's excess population with the deadly virus. His accomplices are two young children - a English speaking boy who's the only survivor of the virus infected Thai village; and a Japanese school girl who's the child of the Professor who developed the virus antidote. His FBI partners are Watari, and Sugura who joins later as a brief comical decoy for L on the run.
这次的电影可说是万众期待的另一章。L在《L change the World》中与主角夜神月展开激烈的头脑战,被认定为天才的“L”。为了把“基拉事件”查个水落石出,选择了一次终极行动,而在采取这终极行动前,他只留给自己最后的“23天”。从L作出这个视死如归的决定的一刻,到最后冲击人心的一幕之间,只有23天。所有人都想知道这23天里面,究竟发生了甚么事?《死亡笔记本》内却没有触及这片空白,”L临终前23天”的一切谜团即将在本片解开!