The summary itself is a wild ride

spoilers ahead

Centuries following the terraforming and colonization of Mars led by humans, a brief but catastrophic interplanetary war takes place between Mars and Earth costing both parties billions of lives. The two planets eventually make peace with each other, and a large-scale colonization initiative is carried out by genetically engineered humans called Star People throughout the galaxy.

Humans (now Star People) then encounter a malevolent and superior alien species called the Qu. The Qu's religion motivates them to remake the universe through genetic engineering. A short war follows in which humanity is defeated. The Qu bioengineer the surviving humans as punishment into a range of exotic forms, many of them unintelligent. After forty million years of domination, the Qu leave the galaxy, leaving the altered humans to evolve on their own. The bioengineered humans range from worm-like humans to insectivores and modular and cell-based species. The book follows the progress of these new humans as they either go extinct or regain sapience in wildly different forms and gradually discover that the Qu experimented on them.

One species, known as the Ruin Haunters, replaces their bodies with mechanical forms using the technology the Qu had left, now known as the Gravitals. They begin to colonize the rest of the galaxy while annihilating most life within it, including the other post-human species (except for Bug Facers whom in a similar fashion like that of the Qu are genetically modified by the Gravitals for their own gain). They are, themselves, destroyed by the Asteromorphs, the descendants of the human species who escaped experimentation by the Qu, the remaining Gravitals are then re-modified into less sophisticated machines to serve as a labor by the Asteromorphs. The final chapters of the book detail humanity's rebound as a posthuman species, their first contact with another galaxy's life, rediscovering and defeating the Qu after five-hundred million years, and concluding with the rediscovery of Earth 560 million years in the future.

All Tomorrows ends with a picture of the book's in-universe author, an alien researcher, holding a billion-year-old human skull and writing that all posthuman species disappeared a billion years in the future, for unknown reasons. The author goes on to state that mankind's story was always about the lives of humans themselves, not major wars and abstract ideals. The author ends by encouraging the reader to "Love Today, and seize All Tomorrows!"

I'm curious how the only printed version wound being in Thai?!