Five prisoners on Alcatraz are offered a pardon for participating in a medical experiment but one of them kills another one of the prisoners and blames the experiment. The doctor (John Howard) and nurse (Joan DIxon) involved in the experiment do not believe the drug was the cause and that it was a premeditated murder and so set out to find the truth. This starts as a medical experiment but develops into a criminal murder mystery. For a low budget B movie this has a surprisingly good storyline.
3/5 
John Howard
Joan Dixon
Walter Kingsford
Robert Shayne