Is Conrad saying then that these two rivers are very different, one good, the other bad? Yes, but that is not the real point. It is not the differentness that worries Conrad but the lurking hint of kinship, of common ancestry. For the Thames too "has been one of the dark places of the earth." It conquered its darkness, of course, and is now in daylight and at peace. But if it were to visit its primordial relative, the Congo, it would run the terrible risk of hearing grotesque echoes of its own forgotten darkness, and falling victim to an avenging recrudescence of the mindless frenzy of the first beginnings.