Jerome K. Jerome 
The Philosopher’s Joke [EPUB ebook] 

Myself, I do not believe this story. Six persons are persuaded of its truth; and the hope of these six is to convince themselves it was an hallucination. Their difficulty is there are six of them. Each one alone perceives clearly that it never could have been. Unfortunately, they are close friends, and cannot get away from one another; and when they meet and look into each other's eyes the thing takes shape again.