That happened to me, but with money. It was my first year teaching .... many,many moons ago.....and I was so proud to be saving my pay to get my parents a great Xmas gift bought with my own money. I was boarding with a family and an envelope with $2000 went missing. Not for a moment did I think the family was to blame as they were as honest as honest come. We searched for a long time and I finally thought it was gone forever, probably lost from my pocket on the way home from the bank.
I left these people at the end of the school year.
The next year they moved to another city. They took out the drawers to move out the bedroom dresser I had used. When they lifted the dresser, the envelope of money slipped out on the floor.
Apparently, I stuffed the money into the back of the drawer and it slipped over the back edge and got stuck between the drawer back and the dresser back panel.
Yes, the drawers had been searched, and we had pulled out the dresser to check the floor behind it, but it stayed stuck up against the back.
What a wonderful surprise when the lady called me to report the find!
So, check out the area down behind the books and other furniture with drawers.
Hope your books are found.