This story opens on a midsummer Sunday, one in which "everyone sits around saying 'I drank too much last night,"' from churchgoers, the priest himself, golfers and tennis players, to the leader of the Audubon Group.

Donald and Helen Westerhazy and Lucinda and Neddy Merrill are sitting by the Westerhazy's pool. Neddy, a youthfully slender man, slid down the banister and jogged to the dining room for coffee. He then sat dipping his hand in the water of the pool, his other hand around a glass of gin, having just gone swimming. Neddy thought about his own house, eight miles to the south, where his four daughters were likely playing tennis.

Neddy made the geographic "discovery" that a map of swimming pools constituted a stream through which he could swim home. He considered himself to be quite brilliant and decided that he would name...