A series of mysterious murders, committed by the poison of a black Mamba, puts London in distress. Scotland Yard's Superintendent Elford suspects that the "Squeaker" is behind the murders - the mysterious stranger, the underworld is afraid of and is unsuccessfully hunted by Scotland Yard. The clever mugger grabs his share of each robbery's loot, in return for not reporting the burglars to the police. Superintendent Elford's investigations lead him to a well-known animal wholesale business, where a Mamba was stolen. The former shopkeeper was blackmailed by the "Squeaker" and subsequently forced to death. His widow, the charming old Mrs. Mulford, now looks after dismissed convicts and has handed over the business to the obscure Frank SutSound. The suspicion focuses more and more on the sly animal keeper Krishna. But one morning he also disappears... 　　译文(2): 一系列神秘的谋杀案，由一条黑曼巴蛇的毒液犯下，使伦敦陷入困境。苏格兰场的负责人埃尔福德怀疑“吱吱”是谋杀案的幕后黑手——这个神秘的陌生人，黑社会害怕，并且被苏格兰场追捕，但是没有成功。这个聪明的抢劫犯从每次抢劫的赃物中分一杯羹，作为不向警察报告窃贼的回报。埃尔福德主管的调查使他找到了一家著名的动物批发公司，在那里一条曼巴蛇被盗。这位前店主被“吱吱”勒索，随后被迫死亡。他的遗孀，迷人的老太太马尔福德，现在照顾被解雇的罪犯，并已将业务移交给鲜为人知的弗兰克萨桑德。怀疑的焦点越来越集中在狡猾的动物饲养员奎师那身上。但有一天早上他也消失了。