I recently watched the 2017 remake of Murder on the Orient Express (after a 1934 novel of the same name by Agatha Christie). The movie and the connection to a train might lend itself to an interesting graphic.

On pinterest, I searched for inspirations regarding train graphics.
See board: (https://www.pinterest.nz/vogt1401/graphic-project-1/)

At this stage I am drawn to a minimalist and modernist design, reflecting the period when the book was written.