Set in the Cold-War era of the early 1950s: Middle-aged Lucy Tamerlane, longing for adventure, takes a position as librarian aboard a luxury round-the-world ocean liner out of New York City. She seems at first a fish out of water, but when several of her patron/passengers fall victim to a mysterious, and fatal, malady, she sets out to investigate in her own amateurish, but charming, way.