and nigel said he didn't know. then the witch said: "i'm not a witch anymore. i'm only a happy old woman, but i know some things still. those whirlpools were made by the enchanter-king's dropping nine drops of his blood into the sea. and his blood was so wicked that the sea has been trying ever since to get rid of it, and that made the whirlpools. now you've only got to go out at low tide."