The Immeasurable Heaven is an imaginative and wild space opera novel written by Caspar Geon, published by Solaris Books. A proposal that promised a different way to approach the genre, blending together science fiction and fantasy in a story devoid of human characters, with an expansive worldbuilding that ends up blowing your mind; be ready to feel confused, but trust the author, because the journey is one to remember.

Our story is set in Yokkun's Depth, a universe filled with different levels of dimensions; a place that is still to be explored, as the journey through the layers (called Phaslairs) is one in only one way: you can always go down to a younger layer, but never up. However, despite being something impossible, somebody is ascending through the Phaslairs, decided to reach the higher Phaslair, no matter the cost.
Whirazomar (Whira for short) is traversing the galaxy in the belly of a sentient giant spore called Gnumph, in order to reach the center and manage to acquire a map of all the realities. At the same time, Draebol, the maker of the map, is quickly jumping towards lower Phaslairs, trying to escape from the multiple people that are trying to capture him; when the ascender learns about the map, they will also act accordingly.

Characterization pales a bit in comparison with how extensive and trippy is at sometimes the worldbuilding, but mostly because the latter captures most of your brain power; said that, Geon still takes the opportunity to develop the characters. Not only we have a Whira who is tied by duty, but still keeping some secrets, carrying most of the narrative weight, but I found myself fascinated by Draebol and his travel through the Phaslairs; trying to escape and constantly changing the form as he traverses from one layer to other. He's tired as his mission has been on the run for an indeterminate amount of time; still, he continues because he feels this is what is right, even if the tax is too high. The encounter between these two characters is also one of the defining moments of the book, an inflexion point in the plot.

I find difficult to convey how unique the whole Yokkun's Depth and its creatures feel; while there's a high level of technology achieved, there's also a biological component that allows for the most imaginative creatures, many of whom manifest incredible characteristics that are used by some of our characters. It is true that this ambition also makes the first half of the book a bit slower than I usually like, with Geon introducing us to the universe and some of its bits through the perspective of an indeterminate narrator from a long time after the story; however, my advice is to just trust the author, let him take you onto Yokkun's Depth and marvel yourself with how many cool creatures there are.

The Immeasurable Heaven is such an unique and imaginative novel, perfect for those that come from a fantasy background but want to deep dive into sci-fi; a space opera that keeps you guessing and trying to understand what's happening, rewarding the patient reader with an excellent climax. I really hope that Geon eventually returns to Yokkun's Depth in next novels; and honestly, here's a candidate to be my novel of the year.