I think the conceptual idea is a fine motivation, but the idea needs a lot more fleshing out. The soulmate status would need to be explained and the 2 lifetimes as well considering these are terms that could mean a variety of things. As for finding soulmates scientifically, that idea sounds a bit…odd to me. I say that since we don’t really have a good standing on what a “Soul Mate” is nor what happened to humans to lead to a status where that’s the only method of reproduction. The concept can work, but it’d require some fleshing out and some proper explanation.
It technically is an entry in a series I want to write, but I’d like to pitch the idea of this specific entry since it’s the one I’ve thought about the most.
The premise is a planet covered in a ruined city that stands with huge skyscrapers. The city is empty save for random oddly disfigured robotic creatures that have some manner of hive mind, but their controller or whatever has perished long ago.
Something about Calliumer that’s rather dangerous is that out of nowhere, sirens around the ruined city will begin to sound. This signifies a ten-minute timer to find someplace before gravity itself shifts. Those unfortunate to be in the clear or a weak building will find themselves falling into the sky to their deaths
The story follows this group of 5 who are called the “wardens”, who watch over the rest of the people (made of many species) on this planet who are in stasis. No one knows why they are here or when they came. What each one of them have in connection with each other. All the Warden’s have for protection is an arsenal of some strange technology, presumably from the world this place “Calliumer” one was and for guidance an instruction booklet containing instructions on how to manage things, grow food, and the role of the wardens. They seek a means to get off this planet. However, there is a rule told in the instructions that there can only be 5 wardens at a time and whenever someone dies a random person will be selected to wake from stasis to take the dead one’s place.
The story follows our main character, who wakes up from stasis according to the rules given. He’s promptly told he has replaced a former warden, who died. As our main character gets used to the role, tensions grow strenuous. Some information that it wasn’t simply death, but a murder begin to show and everyone begins to worry and suspect.