For more than a year, books critiquing Donald Trump, advocating gun control or supporting gay rights have been vanishing from a US library -- only to be found later, mysteriously hidden in dark corners of the wrong shelves.
An anonymous person appears to find a malicious pleasure in hiding "liberal" books that he or she dislikes to prevent others from reading them.
"It's censorship, plain and simple," library director Bette Ammon told local press in Coeur d'Alene, a town in the northwestern state of Idaho.
The books, usually on hot-button political and social topics, eventually turn up -- weeks or months later -- hidden behind other rows or buried deep in the fiction section.
The text most frequently targeted is Michael Wolff's "Fire and Fury," which paints a disturbing picture of a chronically dysfunctional Trump administration in its early days.
"That one has been moved I don't know how many times," said Ammon, who is certain that the disappearances are a deliberate, malicious ploy.
As proof, she cites a note left in the library's comment box in August 2018, shortly after books started vanishing.
"I noticed a large volume of books attacking our President," it read. "I am going to continue hiding these books in the most obscure places I can find to keep this propaganda out of the hands of young minds.
"Your liberal angst gives me great pleasure," it added.
Ammon, however, takes no such pleasure from the mystery.
"It's such a waste of time, and it doesn't accomplish what they set out to accomplish," she said.