朝廷大臣相繼被殺，皇上亦遭殺手行刺，諸葛神侯（董驃飾）遂召弟子「四大名捕」無情（伍衛國飾）、鐵手（張翼飾）、追命（梁小龍飾）及冷血（黎漢持飾）回京護駕。
期間，無情重遇鍾情他的艷無憂（米雪飾），可是無情卻愛上其師姐，讓無憂對二人恨之入骨。無憂為了報復而遭奸人利用，加入了殺手組織「十三殺手」。
諸葛神侯與「四大名捕」竭力追查多宗凶案及保護皇上，誓要追捕兇手及幕後主謀。然而，當他們識破「十三殺手」的陰謀時，卻發現背後原來藏著更重大的秘密。
The ministers of the imperial court were killed one after another, and the emperor was also assassinated by assassins. Zhuge Shenhou (played by Dong Piao) then summoned his disciples "Four Famous Catchers": Qingqing (played by Wu Weiguo), Iron Hand (played by Zhang Yi), Zhuiming (played by Liang Xiaolong) and Lengxue (played by Lai Hanchi) returns to Beijing to escort him. During this period, Qingqing meets Yan Wuyou (played by Michelle) who fell in love with him again, but Wuqing falls in love with his senior sister, making Wuyou hate the two of them. Wuyou was exploited by a traitor for revenge and joined the killer organization "Thirteen Killers". Zhuge Shenhou and the "Four Famous Catchers" worked hard to track down many murder cases and protect the emperor, vowing to hunt down the murderer and the mastermind behind the scenes. However, when they saw through the conspiracy of the "Thirteen Killers", they discovered that there was a bigger secret hidden behind it.
该剧描写了四位武艺、兵器均各具特色，而性格也各有独突的“四大名捕”，追录刺杀皇帝的凶手集团的故事。然而追查的结果，连四大名捕本身也始料不及，所遇到的阻力危险，竟然并非来自凶手集团，而是名捕所意想不到的力量。
全剧过程，峰回路转，揭发了许多令人意想不到的情景，构成一幕连一幕的高潮，他们的矛盾冲突也形成了叠起的激情。
