At a company I worked at the CEO out of the blue called for an all hands, all offices meeting with a few days notice. Everybody who wasn't in the main office had to connect via video link. This had as far as anyone could remember never happened before. There was no agenda and no hints as to what the meeting was about. Even senior managers knew nothing. So obviously rumours started flying, people get nervous, and everybody started looking over their CVs and contingency plans.
Meeting day comes and the CEO proudly announces that the company is getting a brand new logo...