In court for murder, Professor Moriarty is released seconds before Holmes arrives, too late, with vital evidence. Free again Moriarty vows to Holmes that his next crime will be so fiendish and amazing that Holmes's reputation will be finished. Moriarty sets about a fiendish plot involving the crown jewels and a series of mysteries to distract Holmes's mind.I enjoy most of this series as they all seem to run to the same formula. Here the plot goes back to basics and adds more of the mystery and less of the comedy. The plot is an enjoyable battle of wits between the two great minds. The downside is that the side-mystery that Moriarty sets up takes up the majority of the time and the two don't cross swords as well as they do in a gentlemanly beginning. The mystery surrounding Miss Brandon works OK but not really great as you know the whole time who is behind it and why. The jump to the crown jewels is too easily made and is a bit of a letdown.The comedy is less evident than usual but is still there. However it is overwhelmed by the more serious side. Bruce still does well but I was glad that he stood up to Holmes more than usual – telling him off for treating him like a child and such like. Rathbone is a good Holmes but his logic was off here and I wasn't as impressed by him as I usually am. Zucco is an interesting foil, but doesn't get enough time to work here. Lupino in an early role is interesting but a little too heavy and tads to overplay her tension a bit.Overall this is an OK addition to the series. The plot is reasonable but focuses too much on the diversion than the central characters and the reduction in comedy makes it feel a lot heavier than usual.

清朝末年，朝廷腐败，饱受外国侵略者的掠夺。在偏僻小县城龙镇，土毛子为向洋人讨赏而四处搜罗古玩珍宝。小衙内龙大少游手好闲，不务正业，吹牛说见到了真龙，却引来了寻宝的洋毛子。龙大少与之周旋，险遭杀身之祸，幸得侠女山妹相救。为搭救落入洋毛子之手的国宝“大熊猫”，醒悟后的龙大少率领众乡亲轰轰烈烈地与入侵者展开大搏杀……

高级警官康Sir遭人杀害，临死前他销毁了所有卧底的资料，以保护这些游走在生死线上的兄弟。在此之后，警方开始着手恢复数据，与卧底们重新取得联系。女卧底阿钉（佘诗曼 饰）某天收到一条康Sir发明的密码，在刑警男友阿Q（吴镇宇 饰）的指挥下，她尝试与这名神秘卧底进行接触。另一方面，某披着合法公司外皮的黑道组织重要成员阿蓝（张家辉 饰）和邵志朗（古天乐 饰）联手袭击了竞争对手。这二人情同手足，在公司少壮派中风头正劲，如日中天。然而警方对他们行动的预判令阿蓝开始怀疑公司有内鬼存在。经过几番试探，阿钉终于与神秘卧底接头，可是莫大的危险也向她奔涌袭来……

“竖锯”（托宾·贝尔 Tobin Bell 饰）和新学徒阿曼达一起失踪，警方四处搜索，满城阴云密布。一天夜里，刚值完晚班的女医生莲恩·戴伦（巴哈·索莫克 Bahar Soomekh 饰）惨遭绑架，醒来时惊恐万分的莲恩，发现自己被捆绑在一间废弃的空屋里，同屋的还有另一名倒霉受害者杰夫（安古斯·麦克菲登 Angus Macfadyen 饰）。此时“竖锯 ”已卧床不起、奄奄一息，莲恩被告知除非她能在死亡游戏完成前保住这个疯子的性命，否则她和杰夫必死无疑！为了活下去，神经高度紧张、备受煎熬的莲恩想尽办法让“竖锯”保住最后的呼吸。然而她却怎么也想不到，杀人狂暗地里有着更可怕的杀人计划--那将会是恶名彰著的“竖锯”绞尽心血的死前华彩！最后的终极死亡游戏即将开始……