I worked in a department of 25 people for a newspaper publisher. We all had our personality quirks but who doesn't?
One day, we were very close to a deadline but we couldn't find a particular advertisement to be included in the paper (obviously, this was the dark ages where you physically created the advertisement, got it proofread before being placed on a page to be photographed and plated). We dropped everything to look for this advertisement for at least 20 minutes. It finally dawned on us that a woman I'll call, "Ann" had gone to lunch and maybe she had the advertisement somewhere in her locked desk drawer. We had ten minutes before the deadline and Ann still had 40 minutes of lunch break so our boss took his master key and opened her desk drawer.
He just wanted to take a quick look but instead he found a very large stack of papers that were dated (this was May so it was a huge stack!) and on them had a running commentary on every single one of us and what we may have done that particular day to annoy her. She had a "numbered list" of people who were that days worst offenders. She called it her "Gun List".
One thing was really weird (as if this wasn't enough) was that one name was missing on those papers and that was "Mary" who sat next to her. However, under the stack of papers was a notebook titled, "Mary" and it was basically all the reasons she hated her and hoped something tragic would happen to her! She had one with the name of her husband too. Yikes! It was very much a WTF moment!
The advertisement was not in her drawer, btw.
Someone who was in the hall said Ann was on her way back and we all scrambled to put her desk contents back together and pretend we hadn't seen that desk of weirdness!
She came back early because the advertisement jacket with the advertisement had fallen in her handbag and she found it when looking for her purse to pay for her lunch and she knew the deadline was looming. Weirdly, we didn't seem too bothered about it and our boss thanked her for bringing it back and told her to take a full hour for lunch, no probs. The man must have been freaked because he was always in her "Top 5".
She was a quiet person who was always very nice to everyone but from that day, we all stayed well clear of her!