A Case for Dr Morelle was a British radio drama series that aired on the BBC Light Programme in 1957. The show followed the adventures of Dr. Morelle, a psychiatrist-turned-detective, known for solving complex cases with his sharp intellect and psychological insights. The series was created by Ernest Dudley and featured a blend of mystery and detective elements. "The Black Ruby" is the ninth episode of A Case for Dr Morelle, originally aired on June 18, 1957. In this episode, Dr. Morelle investigates the authenticity of a legendary gem known as the Black Ruby. The plot unfolds as he delves into the mysterious circumstances surrounding the gem and encounters various characters with vested interests in its fate.