I’ve previously linked Cetus’ voraciousness to the Lalonde tendency toward alcoholism (especially that of Rose’s mother, the denizens manifesting the heroes’ parents as they do), but through Rose’s treatise on forbidden knowledge it also comes across that Cetus reflects Rose’s appetite for knowledge. in Andrew’s words, Light is “about information” (Book 3, p. 181), and since the rain Rose is expected to play to repopulate the Land of Light and Rain’s seas is genetic information, it’s implicitly information that Cetus has been gobbling up.

so long as we’re saying that Cetus is a substance addict, though, and that information can be contained in water, it seems the intuitive next logical step that alcohol is also information, which seems to be what’s being communicated by Roxy’s bottle of genetic slime - even though practically speaking alcohol only seems to obfuscate information? but there are superimposed juxtapositions here; Rose’s interest in necromancy versus Sburb’s interest in procreation, the insistence that gravity is “nothingness” and yet nothingness is where ideas come from… so alcohol, like its troll “soporific” equivalent, is a medium in which information is dissolved, but not destroyed. (just like a black hole!)

in fact Rose seems to indirectly invoke alcohol’s origins in real-world alchemy - the science of dissolving, rendering and re-constituting materials - during Openbound, when she first starts experimenting with distillation:

DAVE: what in the sweet religious name of jesus h dick are you doing with all these bottles
ROSE: Just a little alchemy.
[…]
DAVE: youre a pretty good hike from the alchemiters
ROSE: The alchemy I’m practicing is a little more old fashioned.
ROSE: You know, there was a time on Earth when alchemy didn’t refer to a process whereby a large device used game constructs to materialize some idealized version of an object out of thin air.
ROSE: Alchemists used to experiment with various substances to transmute them into something more valuable.