Hotels often have a random collection of books available to guests.
There will always be some stalwarts, some predictable choices. Usually books relating to the area you’re in. Probably a copy of the Da Vinci Code, The Time Travellers Wife or one of the Harry Potter series.
Occasionally you find something incongruous. Something that seems desperately out of place.
Next time you go to a hotel, look for the shelf. Study the titles. Pick them up, flick through them – look for signs of use, inscriptions, things which could point to why that random collection of books isnt so random.