Edna May Oliver plays the gawky ,spinsterish and bespectacled amateur sleuth Hildegarde Withers -the sort of person who always carries a neatly rolled umbrella irrespective of the weather-who teams up with wisecracking policeman Inspector Piper(James Gleason)to solve the murder of Gerald Brooks (Guy Usher).The title derives from the murder location -the Battery Park Acquarium. There is no shortage of suspects-from the Acquarium director (Clarence H Webb)to the ungrieving widow of the deceased (Mae Clark)and one of her lovers (Donald Cook).Together they set a trap to unmask the killer.<br /><br />Oliver and Gleason work well together and they are blessed with a witty script by Willis Goldbeck as well as some pacey direction from George Archainbaud <br /><br />This was the first of a series and is a good example of solid studio professionalism from its era