edna may oliver play the gawky and spinsterish and bespectacled amateur sleuth hildegarde wither the sort of person who always carry a neatly roll umbrella irrespective of the weather who team up with wisecrack policeman inspector piper ( james gleason ) to solve the murder of gerald brook ( guy usher ) . the title derive from the murder location the battery park acquarium . there be no shortage of suspect from the acquarium director ( clarence h webb ) to the ungrieving widow of the decease ( mae clark ) and one of her lover ( donald cook ) . together they set a trap to unmask the killer . oliver and gleason work well together and they be bless with a witty script by willis goldbeck as well a some pacey direction from george archainbaud this be the first of a series and be a good example of solid studio professionalism from it era .