The story involves an intricate series of time-travel journeys. It begins with a young man speaking to the narrator, the Bartender, in 1970. The young man is called the Unmarried Mother, because he writes stories for many of them presumably from the point of view of an unmarried mother.

Cajoled by the Bartender, the Unmarried Mother explains why he understands the female viewpoint so well: he was born a girl, in 1945, and raised in an orphanage. While a fairly ugly teenager in 1963, he was seduced, impregnated, and abandoned by an older man. During the delivery of her child, doctors discovered he had an condition: internally, he had both male and female sex organs. Complications during delivery forced them to give him a sex change. The baby was later kidnapped and not seen again. The now-former girl had to adjust to being a man and surviving as such, despite being unprepared for any attainable job. While he still identified as a girl he had taken lessons, hoping to get into space as a comfort worker for workers and colonists. Disqualified for such work by the physical aftereffects of childbirth, he used his secretarial skills to type manuscripts, and eventually began writing.

Professing sympathy, the Bartender offers to top his story. He guides him into a back room, and casts a net over the two of them. This is part of a The young man is set loose in 1963 where he dates, falls for, seduces, impregnates, and leaves a young girl; at the same time the Bartender goes forward eleven months, kidnaps a baby and takes it to an orphanage in 1945. He then returns to 1963, and picks up the Unmarried Mother, who is just beginning to realize what has happened. As the Bartender tells him, "Now you know who he is—and after you think it over you'll know who you are . . . and if you think hard enough, you'll figure out who the baby is . . . and who I am."

The Bartender then drops the Unmarried Mother—his younger self—at an outpost of the Temporal Bureau, a time-traveling secret police force that causes events in history to protect the human race. He has just recruited himself.

Finally the Bartender returns to 1970, arriving a short time after he left the bar. He allows a customer to play  on the  having yelled at the customer for playing the song before he left. Closing the bar he time travels again to his home base. As he beds down for a much deserved rest, he contemplates the scar left over from the  performed when he gave birth to his daughter, father, mother and entire history. He thinks "I know where I came from—but where did all you zombies come from?".