1) boy (Andrew Harlan), down on his luck, meets girl (Noÿs Lambent)
2) boy, smitten by girl, gets into even worse trouble
3) boy gets pissed at girl
4) girl saves boy
5) boy forgives girl, they live happily ever after.
Andrew Harlan is down on his luck because he works in Eternity. It is his job to travel in Time and make Reality Changes, such as Reality Change 2456-2781, Serial Number V-5, which destroys the "very beautiful" electro-gravitic spaceships of the 2456th Century. Harlan is one of the despised technicians of Eternity who must do the dirty work of time travel. Space travel never leads to anything but failure and wasted effort and by a quirk of Time, electro-gravitic space travel also leads to high levels of drug addiction. To protect humanity, and that is the purpose of Eternity, electro-gravitic space travel must be edited out of Time, and Harlan is the one who kills it.
As a Time Travel Technician, Harlan is shunned by his fellow Eternals. Beyond the special hardships associated with his specialty, living conditions inside Eternity are not good for anyone. Like all Eternals, Harlan has been ripped out of Time and isolated from his roots in his homewhen. It is a fact of Time and time travel that women can almost never be removed from Time and recruited to work within Eternity. When Harlen meets Noÿs he falls in love and will do anything to keep her, even commit crimes.
Harlan's infatuation with Noÿs comes to an end when he realizes that she is a secret agent from the far future who has traveled back in time on a mission to destroy Eternity. Harlan is ready to murder Noÿs in order to prevent her from destroying Eternity. Noÿs explains to Andrew that Eternity is BIG MISTAKE. As long as Eternity exists and time travel is used to "make things better" for people, humanity is condemned to a safe but boring future. Eventually, humanity, having remained trapped on Earth, becomes extinct. In order for humanity to have a chance for survival, Eternity must be destroyed and humans must spread to other planets in the galaxy.
Andrew thinks about his miserable life as an Eternal and decides to trust Noÿs. Rather than kill her, he helps to end Eternity and produce a Reality Change in the 20th century that will allow humans to reach the stars.
The Start of Eternity tells the "story behind the story". Eternity is the creation of a robot, R. Gohrlay. Gohrlay has tried to use time travel as a way to satisfy the Zeroth Law of Robotics. Eventually, Gohrlay realizes that her effort is a huge error. She recruits Noÿs to be the human agent who destroys Eternity.
Out of the frying pan and into the fire. With Eternity destroyed, Gohrlay has a new plan for how to protect humanity. Humans must form a group mind, linked by telepathy. Humans must be genetically engineered to have an innate set of behavioral patterns that will allow them to function as selfless components in a vast super-organism. Gohrlay launches humanity to the stars and brings into existence Galaxia. Of course, she is unable to see that her plans for Galaxia are as futile as was Eternity. Gohrlay is caught up in a "Dramedy of Errors"* that plays itself out on a cosmic scale, as told in The Start of Eternity.
* The Start of Eternity is not a dramedy in the television sense of the word. It is dramedy in the sense of mixing the classical meaning of "comedy" (a story with a happy ending) and "drama" in the context of a "dramatic novel" where Gohrlay is the protagonist who must struggle to protect humanity from the alien Huaoshy.