And Then There Were 63: The Man in the Brown Suit by Agatha Christie

This is about as close as an Agatha Christie novel gets to an
episode of "The Love Boat," and in some ways it gets kind of close!
Climb aboard as we journey from England to South Africa with our
plucky heroine Anne Beddingfeld, getting embroiled in murder,
diamonds, espionage, and of course romance along the way.... Are
there all sorts of troubling implications in this rollicking
adventure of both the gender and race relations variety? Of course!
Let's try untangling it together.