Cancer of the existence.

 According to natural foresight, the Sun will one day explode, the solar system will one day cease to exist, and even long before any of that, all life on Earth will already have come to an end. But even these do not bring me any comfort: I know that those beings won’t stay in place, that they will leap onto other planets. Even if their planet is destroyed, this time they will be living somewhere else—perhaps on a different world. In other words, they will metastasize. Because they are more than just the cancer of the Earth; they are the cancer of space itself. Just as they spread across the Earth, so too will they spread across the universe.