In Asimov's time travel novel, The End of Eternity, the "hook" is a moment of tension for Andrew Harlan as he travels through time on a criminal mission that he hopes will allow him to rescue his beloved Noÿs and prevent her from being lost in Time. Asimov then had to step back and make the next four chapters be a "flashback" that explains events leading up to Andrew's crime of falling in love with a Timer.
For The Start of Eternity, most of the characters are robots and aliens and I'm reluctant to try to start the novel with a scene that has its focus on non-humans. I'm now thinking that the human character who will get the most development is Gohrlay. I provided a concise description of the rather unusual "life story" of Gohrlay in my last blog post. Gohrlay starts life as a Neanderthal, has her mind transferred into a robotic body then eventually has her mind transferred again into the brain of a modern human.
I can imagine good reasons for beginning The Start of Eternity with a scene about either Gohrlay the Neanderthal or Gohrlay the modern human. The story of "Gohrlay the Neanderthal" will actually be the story of the origin of positronic brains. The story of "Gohrlay the modern human" will include the climax of the "war" between Gohrlay and aliens that is central to The Start of Eternity. I've been planning on putting the story of how Gohrlay the robot invents time travel technology at the very end of The Start of Eternity. Gohrlay's defeat at the hands of the Huaoshy is in the middle of The Start of Eternity.
That leaves "Gohrlay the Neanderthal" as a "logical" starting point for The Start of Eternity. Marvin Minsky's science fiction novel, The Turing Option, describes how a damaged human brain is converted, piece by piece, into electronic circuits that take over the brain functions. I'm imagining a similar process that will convert Gohrlay the Neanderthal's brain into the first positronic brain with human-like thought processes. I have not yet decided if the "conversion" will be a destructive process that kills Gohrlay, although that might be the most dramatic approach. An alternative would be to have Gohrlay survive and participate in helping the "newly programmed" positronic brain learn how to function correctly.
I've been thinking about the origins of each of the Laws of Robotics. I can imagine that Law #2, obey orders, might have come first. It might be possible to make two "short stories" about how Law #3, protect your own existence, and then Law #1, protect humans, are later added as fundamental parts of positronic brains. I've been toying with the question of what the first ever use of time travel might be. Could there be an "upwhen hook" showing how R. Gohrlay travels back in time in order to help facilitate the creation of either her own positronic brain or the Laws of Robotics?