I recently tore through JN Chaney's Variant Saga, a four novel series that starts as dystopian sci-fi and turns into a fantastic first contact adventure.
Once I started reading JN Chaney's The Amber Project I could not put it down. When I finished I immediately launched into the next book in the series. Chaney's post apocalyptic dystopia contains so many interesting facets, I was constantly in a state of needing to read what comes next.
The Amber Project starts the series off focused on Terry, the star genetic experiment of a last ditch project to save humanity from Earth's environmental collapse. 200 years prior something caused the planet to be overcome by a toxic gas that killed everything it did not mutate horribly. A small group of humans have managed to survive in an underground city, but slowly the systems have failed beyond their ability to repair and without access to new resources the end is near.
Science may have hit a home with Terry and his pals, but you can trust teenagers to make things interesting. Naturally, epic self involvement, and epic self sacrifice are involved.
As the series progresses it changes from silo based doom-and-gloom dystopia to trans-dimensional traveling first contact story. As Terry's society begins to discover what happened to the Earth, and who did it, a wild tale spanning at least two universes spins out. I was initially caught a bit off guard, as I didn't expect Avatar to suddenly spring up in the middle of Das Boot, but that is what happens and it is actually pretty good.
Start with The Amber Project, but you'll end up reading the whole series just to see how it all ends. I was able to read them all via Kindle Unlimited.
The Variant Saga (4 Book Series) via Amazon