Q

the long version

Shortly before his wedding, the unnamed hero of this book is visited by a man who claims to be his future self and who tells the hero he must not marry the love of his life, Q. At first the protagonist doubts the stranger, but then becomes convinced of the authenticity of the warning and leaves his financée. More appearances by future selves give other warnings until the only constants in the protagonist's life is his love for his New York City home and his former fiancée Q.