Barnabas, Quentin and the Magic Potion (January 1971)

This story marks a sudden shift in the characterization of Quentin Collins, who up to this point in the range had been portrayed as an enemy of Barnabas. Barnabas predicts trouble for Collinwood when Nicholas Freeze, in whose antique shop Carolyn Stoddard works, discovers a centuries-old potion that promises eternal youth. Soon after, Mr. Freeze's daughter, Hazel, tricked into taking a serum, dies. Carolyn is grief-stricken over her friend's death. Barnabas insists she stay on at the shop to watch Nicholas Freeze and his associates, one of whom Carolyn suspects is Quentin Collins, back at Collinwood in a disguise.

Then Carolyn sees Hazel's ghost.

She interprets this as a warning that Mr. Freeze has marked her for his next victim. Barnabas still refuses to let her quit.

Has Barnabas made a fatal mistake by deliberately endangering Carolyn's life? Or will his plan avenge Hazel's murder and put her spirit to rest?