Cambridge students have been hiding chocolate around the library for their peers to enjoy during exams.
A student at the university's all-female Newnham College found chocolate bars hidden in a hollowed-out book in the library, the Cambridge News reports.
The treats - bars of Cadbury's Dairy Milk and Crunchie - were accompanied with a note that reads:
"Dear Student, Congratulations on finding this book! Take your prize and return with one for the next person."
The original altruist is unknown, and they may have started a long chain of giving before the trick was reported.
But this secret saint did commit that cardinal sin of destroying a book. Most of the pages had a large rectangle cut out, forming a small tray to hold the chocolate bars in.
Thankfully, the book in question does not belong to the library - otherwise university officials might have started investigative and disciplinary procedures to catch the vandal.
A spokeswoman for Newnham College, Jo Tynan, told the Cambridge News:
“We don’t know how long the book was there for but we don’t think it was very long.
"We didn’t think anything like this had ever happened before but when we wrote about it on Facebook we had quite a few responses from alumna.
“One person said she found a pack of minstrels in a book and another student found a love letter. We didn’t think there was form for it but we are not always privy to what the students do.”
The Cambridge News also reports that Newnham College sometimes leaves sweets around the library for students working late during the exam period.