The Hitch Hiker's Guide to the Galaxy is an indispensable companion to all those who are keen to make sense of life in an infinitely complex and confusing Universe, for though it cannot hope to be useful or informative on all matters, it does make the reassuring claim that where it is inaccurate, it is at least definitively inaccurate. In case of major discrepancies it is always reality that's got it wrong.

So for instance, when the Guide was sued by the families of those who had died as a result ot taking the entry on the planet Traal literally (it said 'Ravenous Bugblatter Beasts often make a very good meal for visiting tourist' instead of 'Ravenous Bugblatter Beasts often make a very good meal of visiting tourists') the editors claimed that the first version of the sentence was the more aesthetically pleasing, summoned a qualified poet to testify under oath that beauty was truth, truth beauty, and hoped thereby to# prove that the guilt party in this case was life itself for failing to be either beautiful or true.

The judges concurred, and in a moving speech held that life itself was in contempt of court, and duly confiscated it from all those present before going off for a pleasant evening's ultragolf.

The Guide's omissions are less easily rationalised. There is nothing on any of its pages to tell you on which planets you can expect suddenly to encounter fifteen mile high statues of yourself, nor how to react if it is immediatelyapparent that they have become colonies for flocks of giant evil smelling birds, with all the cosmetic problems that implies.

The nearest approach the guide makes to this matter is on page seven thousand and twenty three, which includes the words 'Expect the Unexpected'. This advice has annoyed many hitch-hikers in that it is a) glib, and b) a contradiction in terms.

In fact, the very best advice it has to offer in these situations is to be found on the cover, where it says in those now notoriously large and famously friendly letters 'DON'T PANIC'.