Two cops are shot dead in cold blood, the killer is on the loose, and a woman lies dying in the hospital of diphtheria. Two completely unrelated cases, but nothing is as it seems in KILLER BY NIGHT. As the highly contagious diphtheria begins claiming more victims, Dr. Larry Ross (Robert Wagner) races to find it's source to prevent an outbreak. More concerned with the dead police officers, Captain George Benson (Greg Morris) reluctantly cooperates with Dr. Ross. The deeper the investigations go, the more they seem to have in common, and the key to solving both of them may hinge upon the only person who might be able to identify the gunman a blind nun. Using the backdrop of a deadly outbreak KILLER BY NIGHT crafts a tense and human thriller. Featuring an original score from the legendary Quincy Jones and an all-star cast led by Robert Wagner and Greg Morris, the film also includes strong supporting performance by Robert Lansing, Theodore Bikel, and Diane Baker.