All tomorrows is one of my favorite work of fiction, it has such a rich and powerful worldbuilding that I'm afraid the summary I'll write won't give it enough justice. So, similarly to what I did with my summary of "Monster", I picked a summary that was written on goodreads by the author himself who explains well the most important plotpoints of All tomorrows

"The story begins in the near future, as burgeoning population pressures force humanity to terraform and colonize Mars. After a brief but violent civil war between the two planets, the genetically engineered survivors begin a new wave of colonization, spreading across the galaxy. Everything is looking up for the human race... until the colonies encounter the Qu, technologically advanced aliens on a religious mission to remake the universe."

"Although humans fight valiantly, the Qu easily overpower humanity; as punishment, the aliens decide to genetically modify the survivors, turning most of them into mindless, animalistic creatures before departing."

All tomorrows takes place millions of years into the future where a broken humanity, scattered through space on different planets, will persevere to survive and will discover the twisted story of their origins.