The speaker begins by telling you that you have already lost the argument. A beast is running, it eats light, and nothing you say will change its appetite: "you cannot teach the beast / to love the light." The title calls it a Leviathan, the sea monster of ancient scripture, and says it is "flowering out from the Great Time-Heart." The poem never says what the beast is, but the clues point toward time, or toward some huge, blind process like entropy that wears light down as it goes. The title's strange verb matters here. Monsters don't usually flower. The word suggests the beast is not an invader but something natural, grown from the core of things.
The poem's shape suits that idea. It has three stanzas of four, four and five lines, with no rhyme, no capital letters and no punctuation at all. Nothing in the lines stops the reader, so the poem keeps running just as the beast does. "The beast will run on" also quietly puns on the run-on sentence, which this text really is. That line returns at the start of the last stanza and again a line later, a chant that makes the poem sound like a warning passed from one generation to the next. The second-person "you" supports the effect. The speaker sounds like someone giving calm advice about a danger that can't be avoided.
The three failed methods rise in force. You cannot *teach* the beast, which means persuading it. You cannot *stop* it, which means opposing it by strength. You cannot *train* it, which means taming it by discipline. Persuasion, force and obedience are the ways people usually deal with powerful things, and the poem closes all three off. Then it adds "mindlessly," and any hope that the beast might be reasoned with disappears. It is not cruel, since cruelty needs a mind. "Mauling career" gets the same effect from a pun: "career" means both a headlong rush and something like a profession, as though devouring were simply the beast's job.
The middle stanza is where the poem turns, and its imagery is the most surprising. Instead of fighting, you "offer yourself as a light-seed in its path." The seed picks up the "flowering" of the title and makes the sacrifice a kind of planting. Then the poem gets blunt: the beast "digests you and excretes you." There is nothing heroic in that, and the speaker doesn't pretend otherwise. Still, "some of the dark will part in its wake." A wake is the trail a ship leaves in water, which fits a sea monster, and it is also the vigil kept after a death. Both meanings fit. The word "some" keeps the claim small and honest.
The stanza ends with its strangest line: "you ate the wedge / that gives darkness a horizon." The grammar is slippery. The beast does the eating everywhere else, so why does "you" suddenly eat? One reading is that, once swallowed, the light-seed has taken a wedge out of the dark from inside. A horizon is where dark meets light, so darkness with a horizon is darkness with an edge, a place you can steer toward. Without it, the dark would be total and formless. The sacrifice does not defeat the dark. It gives the dark a shape.
The last stanza refuses to celebrate. The beast runs on, "dragging / the whole horizon with it." The line break itself drags, because "dragging" hangs at the end of the line and pulls the reader into the next. The ending can be read two ways. The horizon you made may be carried forward and keep being useful. Or the beast may be taking it away, so that every edge you create gets dragged off with everything else. The poem doesn't choose between these.
That refusal is what makes it worth reading. It borrows a huge mythic monster and a cosmic setting, and the name on the byline, Q.R. Quasar, seems to point toward astronomy as well. But it turns them toward a small question: what is the point of a single act of light against something that cannot be beaten? Its answer is neither despair nor comfort. You will be eaten, but you can still leave the dark slightly less shapeless than you found it.