Holmes and Watson search for two murderers after a base jumper is shot out of the sky by one killer, and has his parachute sabotaged by another. Also, after Joan's sister, Lin, thinks she sees Shinwell with a member of his old gang, Joan takes drastic measures to make sure he won't be drawn back into a life of crime.

When Shinwell comes to Holmes and Watson for help after he's framed for a gang killing, they have three days to find the real murderer before he is arrested and sent back to jail.