In Heinlein's story, a man in a barroom tells the bartender a story starts when was a little a girl called Jane. She was born in 1945 and abandoned at an orphanage, grew up awkward and ugly, and finally met an older man who seduces her. Jane becomes pregnant and has a difficult delivery by Cesarean. She receives the news that due to difficulties in the birth, the doctors performed a complete hysterectomy. But they also learned she had a set of male organs and with surgery and hormones, Jane becomes John, the man in the bar telling the strange tale. Another blow to Jane is that her baby is kidnapped. The bartender explains he is a time traveler and takes John back in time to when he as Jane met the stranger to kill the man. Of course, John falls in love with Jane his younger self, seduces her and she become pregnant, thus making him the older man. Meanwhile the bartender travels ahead in time to the hospital and kidnaps the baby taking it back to 1945 and abandons it at the orphanage. The story become the Bootstrap Paradox where a future event is passed to the past creating the present and ultimately its own future.
The story was made into movie recently with Ethan Hawke and Sarah Snook. Predestination explores the Bootstrap Paradox staying remarkably close to Heinlein's story. Here is a trailer.
Some quotes too from the movie.
" What if I could put him in front of you? The man that ruined your life. If I could guarantee that you'd get away with it, would you kill him?"
"Here you are at the beginning of your new life. It can be overwhelming knowing the future you're about to create. Knowing the purpose of that life. You know who she is. And you understand who you are. And now maybe you're ready to understand who I am. You see, I love her too."
"You'll have to make tough choices. You'll influence the past. Can we change our futures? I don't know. The only thing that I know for sure is that you are the best thing that's ever happened to me. I miss you dreadfully."
A great story and a great movie for all you time travel aficionados.