SciFi and Fantasy Book Club discussion

Are there any books (or movies for that matter) that literally never introduce another character? The closest Ive read was The Purple Cloud by M.P. Shiel where a second character doesnt get introduced until almost the end. Of course I understand that its quite possible a book like that could be indeed boring (maybe thats why its never, or rarely ever) been done), but Ive always been extremely curious as to whether there was any author out there who had done it...

Here's an esoteric answer: there's a short story in either the 1953 or 1955 'best science fiction short stories', edited by T. E. Dikty. The story hypothesized, before any space flight had occurred, the first space flight into the Van Allen belt would ignite a massive fire/explosion killing all life on earth. The returning spaceship, with one man on it, landed near an ocean, and the man waded into the ocean, died, and his remains provided the cells that eventually created new life on earth.

These annuals by Dikty were possibly the first SF anthologies published in the US...I inherited copies that were lost by the postal service during a move several years ago...hence no citation.

There's an esoteric answer for you Ubik! I know there are lots of others, but am not recalling them at the moment.

Is it this one: Year's Best Science Fiction Novels 1953? If so, which story?

One of my all time favorite short stories which I read in a grade school literature textbook was entitled "Xong for Xuxan" by Russell Ray and only had one character, Susan, and was told in first person. It's hard to find. It's in a couple of anthologies and was originally published in Playboy in the early 1960s. I have the text somewhere on my computer at work if you're interested.