It set out on the journey, but long before it reached the food, its energy ran out. Mass, converted back to energy to make the trip, was used up. It shrank.
Finally, all the energy was gone. It was a spore, drifting aimlessly, lifelessly, in space.
That was the first time. Or was it? It thought it could remember back to a distant, misty time when the Universe was evenly covered with stars. It had eaten through them, cutting away whole sections, growing, swelling. And the stars had swung off in terror, forming galaxies and constellations.
Or was that a dream?
Methodically, it fed on the Earth, wondering where the rich food was. And then it was back again, but this time above the leech.
It waited, but the tantalizing food remained out of reach. It was able to sense how rich and pure the food was.
Why didn't it fall?
For a long time the leech waited, but the food stayed out of reach. At last, it lifted and followed.
The food retreated, up, up from the surface of the planet. The leech went after as quickly as its bulk would allow.
The rich food fled out, into space, and the leech followed. Beyond, it could sense an even richer source.