Gabriel Fielding's books, the fine, consistent ones about the Blaydon family and then his Hitlerian The Birthday King, established that he is a very sound novelist: he writes about characters that seem to exist and events that certainly could have happened. This book, lighter in tone, although its realism is much too abrasive to class it as entertainment only, deals with three gentlemen in their off season-- of infidelity. Two of them, who work at the B.B.C. and express their intentions with confidential complicity over lunch, are Randall Coles, 49, and Presage, pushing 48. The memory of Coles' once beautiful Letitia reduces her now to the actuality of cold cream, hair curlers and worthwhile activities: Presage's wife hardly appears. Coles, through a prisoner in the Jail to whom he ministers advice, becomes involved with the prisoner's wife-- a common sort who although she concludes that sex is ""just a blooming waste of time,"" has been generally free with it (the man her husband killed; a rug cleaner salesman; and now Coles). Presage has an exhausting weekend with the much more youthful, playful Hera. There is very little actions with occasional slow stretches between the confidences and their fulfillment, and it involves the escape of Coles' prisoner and his death.... Fielding's matter of fact commentary is often sharp and funny; but it's almost too uncomfortable to be attractive which serves a moral purpose one is sure Fielding did not intend.