A bout of paranoia hit the Association of University Teachers this week as it prepared for Tuesday's momentous one-day strike.
First, union chiefs suspected the Government's motives for changing the publication of its industrial relations green paper from Monday to Tuesday, claiming it was trying to divert media attention from the strike.
Next, there was a bomb scare, leading to a further rash of speculation about dirty tricks.
An AUT spokesman said: "We were very busy on Monday fixing up strike coverage with all the TV stations and national newpapers when we had to evacuate the building. At least one wag suggested that the hoax call might have come from the DfEE."