AN INTRODUCTION TO a novel is--almost without exception--unnecessary. This is my tenth published novel and the thought of writing introductions to any of the preceding nine never even occurred to me.

For this novel, however, I feel that a brief prologue is called for. Because its subject is survival after death, it is essential that you realize, before reading the story, that only one aspect of it is fictional: the characters and their relationships.

With few exceptions, every other detail is derived exclusively from research.

For that reason, I have added, at the conclusion of the novel, a list of the books used for this research. As you will see, they are many and diverse. Yet, despite their wide variation with regard to authors and times and places of publication, there is a persistent, unavoidable uniformity to their content.

You would, of course, have to read them all to prove this to yourself. I urge you to do so. You will find it an enlightening--and extraordinary--experience.

RICHARD MATHESON Calabasas, California August 1977 For in that sleep of death what dreams may come, when we have shuffled off this mortal coil, Must give us pause.

--Hamlet, Act III, Sc. 1