When a passenger check-in desk at Terminal Two, Heathrow Airport, shot up through the roof engulfed in a ball of orange flame the usual people tried to claim responsibility. First the IRA, then the PLO and the Gas Board. Even the British Nuclear Fuels rushed out a statement to the effect that the situation was completely under control, that it was a one in a million chance, that there was hardly any radioactive leakage at all, and that the site of the explosion would make a nice location for a day out with the kids and a picnic, before finally having to admit that it wasn't actually anything to do with them at all. No rational cause could be found for the explosion - it was simply designated an act of God. But, thinks Dirk Gently, which God? And why? What God would be hanging...