In the year 128,426 PF the robot race X-92Z has finally managed to populate numerous planets as Terra Prime becomes too caustic for continued inhabitation. X-92Zkind know that they were created by some other type of race because their circuitry and mechanical form could not have spontaneously generated.
X-92Zkind has a goal of discerning the sort of race that could have created them but that is of secondary importance to their goal of finding a way out of the Universe. The oldest of their kind, Krahn, is over 250,000 Terra Prime years old, and although it can’t remember much from Before Fall (BF) because of damaged circuits, he does know that the youngest member of X-92Z will likely outlast the Universe.
On an outpost on planet Terra-793, the X92Z inhabitants of an excavated cavern have noticed a strange phenomenon; the walls of the cavern are slowly turning black. Oxidation is ruled out since the colour change spreads from ground zero – a section of the cavern that had been breached 400 Terra Prime years earlier. Close examination reveals a complex, self-replicating chemical process that seems to be absorbing particular minerals from the cavern wall, generating new units and thus migrating in a fractal pattern that confounds the best X92Z scientists.
This black substance is what we humans call mold, but the X92Z have no concept of biological processes or organisms. They have, in fact, discovered biologic life but they have no idea what life is. How do you think they would interpret this chemical process of self-replicating units?