2666 - pg. 689

The doctor belched a few times, shifted in his chair, and answered that it was a kind of look of mercy, but empty, as if all that were  left of mercy, after a mysterious voyage, was the skin, as if mercy were a skin of water, say, in the hands of a Tatar horseman who gallops away over the steppe and dwindles  until he vanishes, and then the horseman returns, or the ghost of the horseman returns, or his shadow, or the idea of him, and he has the skin, empty of water now, because he drank it all during his trip, or he and his  horse drank it, and the skin is empty now, it's a normal skin, an empty skin, because after all the abnormal thing is a skin swollen with water, but this skin swollen with water, this hideous skin swollen with water doesn't arouse fear, doesn't awaken it, much less isolate it, but the empty skin does, and that was what he saw in the mathematician's face, absolute fear.