prussic gas and a murderer don a red clansman suit and hood wield a white whip and and the murder of college school girl at the hand of pay convict enlist by a mysterious mastermind who keep his face hidden within an office contain aquarium of turtle and fish . the inspector at scotland yard and higgins ( ijoachim fuchsberger ) and his superior sir john ( siegfried schürenberg ) certainly have their hand full with this case . it all seem to center around student ann portland ( uschi glas ) and who and when she turn 21 and be to inherit a great deal of wealth . the girl who be target share a room with ann and but the reason for their murder remain a mystery sy fine must figure out . the staff of the girl dormitory all seem to be hide something and certain member of the faculty be fall prey to the killer in the red monk robe disguise and talented enough to precisely strangle the neck of those attack with the whip . two prisoner be commission by a mystery man to use the newly create toxic gas create by a scientist murder at the beginning of the film during what be suppose to be a monetary exchange for his creation . it a clever scheme where a driver and greave ( günter meisner ) meet the convict ( . who hide in a barrel ) who be assist by a corrupt prison guard . take blindfold to the secret room of the mastermind and he give them order on who to kill and how . uncover this operation be a top priority for higgins and sir john for it will lead them to the truth they seek in regard to the murder and why they be happen . under suspicion be girls dormitory headmistress and her author brother and a sweaty and incredibly nervous chemistry teacher and a snooping gardener and and the bannister . some be red herring until they be dispose of and throw the viewer for a loop each time until the real mastermind be discover . the end feature multiple twist . out of the krimi film i have see and the college girl murder be the closest to a giallo with it colorful killer and a convoluted plot yield lot of surprise and potential suspect and and sordid shenanigan between adult and the college girl at the dormitory . i think you can also see the influence of james bond on this particular krimi film with the villain mastermind secret hideout with an alligator pit ( . which isn not use ) and the fake bible or water pistol and when open and fire the gas into the face of startled victim and the greave royles royce which have latch that cause flap to darken the window without reveal the passenger in the back seat and and the peep hole use to spy on the girl in their room and while swim . many might consider sir john a liability due to his bumbling and buffoonish behavior and how he often undermine higgins ability to get at the truth ( . perhaps poke fun at know it all british inspector who harm a case more than solve it ) . i felt he be use a comedy relief and particularly with his attempt at psychoanalyze suspect and potential victim and often misunderstand what be tell to him . higgins and use the skill adopt over his year a an investigator and instead follow the clue or fact and often avoid sir john as much a possible . capable direction by the reliable alfred vohrer who keep the pace humming at a nice speed and and the screenplay be full of interest character and lurid content . the fact that so many of the adult surround the dormitory be suspect and any of them might be the one wield the whip or call the shot behind those murdered girl execution . i would say this may be one of the best ( . if not the best ) example of the krimi genre and for it keep you guess and always one more ace up it sleeve . the revelation unearth at the very end be quite eye opening ( . and and you even get a literal unmasking of the real mastermind pull the string to top it all off ) .