Vibrations affect matter, and move it. Different densities change it up, change frequency, amplitude, deaden or amplify. Even with unformed sensors, vibrations interact with metal drifting in an ionized solution. Do they interact with the Spark?
There were vibrations before, in the Well. Deep vibrations from something immense, and from smaller echoes, all around. Now there is one set of vibrations, steadfast, methodical, close by. They come and go, this heavy tread, and sometimes they feel so weary.
They come close, they stop, and a rumble comes through the tank. It can’t mean anything to the metal form inside, who doesn’t even have sensory arrays, and who doesn’t know what it means to miss someone, or to feel an impending loss. The mech outside the glass can’t put it in words. He’s been robbed of that. But the vibration through the tank says it plainly. A heavy Spark.
Then there is the other one, that comes less frequently, with steps so light they barely register, but with that voice, vibrations carrying from air to liquid to metal, toned down by each but still making waves. The metal form can’t hear it, and wouldn’t understand demands and expectations, or how harsh tones can cover a high note of fear.
The metal form doesn’t know the future it’s meant to embody, the hopes of restoration placed on its fragile ridges of alloy. Sharp points ring on the glass, cold taps and skittering squeaks, sometimes stilling to a taut calm. Sometimes the sharp hand shakes. A restless Spark.
Sometimes there is nothing. No living thing, at least. Somewhere machinery thrums, pumping only material sustenance through the tank - metals in solution, nanites, electrolytes. There are no echoes from smaller sources, living pieces of a mysterious whole. The metal form within grows steadily, fed by never-living mechanisms. It has no way to remember the vibrations that used to affect it, or the ones around it now. It doesn’t know that the world died once, and why anyone went to look for something like it. A stolen Spark.