In a mid town apartment, a girl listens to her companion play her a tune on the piano, when she is set upon and strangled. Three days later, her distraught brother takes the case to Mr Keen. A motive begins to develop when an inheritance is mentioned, and might there be a hint of Jealousy in the brother’s act?
Mr Keen goes to the piano school to get more details, and finds a man who seems to be bordering on the brink of sanity as he displays his emotions at the girls loss. Mike and Mr Keen head off to her apartment to see what turns up there. It would have taken a good deal of strength to have strangled a person, and Mr Keen finds a suspect there who would just fit the bill.
In his office, Mr Keen and Mike discuss the points of the case. More plot twists emerge, but does it clear matters up, or make things more muddy? The girl was killed only days after emptying her bank accounts, the wife of the emotional man testifies to Mr Keen on his behalf, and suddenly a phone message that another life may be in danger. Mr Keen rushes out to the rescue.
With all the smoke and mirrors, and evasive behavior going on, Mr Keen isn’t thrown off the track. He confronts the killer, and tells the story.