Yylimium is a quantum superposition polyelement found in trace amounts on most solid-crust planets, but particularly prevalent on Viridia Prime and nearby worlds. Yylimium’s achronic instability makes it a vital fuel component as well as a potent weapon. It is not the job of a historian to speculate as to the prevalence of yylimium on Viridia Prime nor its peculiar role in that planet’s evolution, but merely to note two facts:

1. It is well known that worldminds can manifest across time and space in diverse fashions. The White Flower Dreaming, for instance, is most often perceived as a peculiarly comforting musical dissonance (you may have heard it yourself while drifting off to sleep), while the Knosis is known to be identical with a certain large prime number.¹
2. Urgency-era transcripts confirm that the Nova Entity had a seemingly first-hand knowledge of the location and distribution of yylimium deposits, although this knowledge was less useful after the destruction of the Third Nova Generator.

—Thucydides Plutonium