"You’re not the only one who calls them that; the other Downworlders do the same,” said Will. “I discovered that fact while investigating the symbol. I must have carried that knife through a hundred Downworld haunts, searching for someone who might recognize it. I offered a reward for information. Eventually the name of the Dark Sisters came to my ears.” “Downworld?” Tessa echoed, puzzled. “Is that a place in London?” “Never mind that,” said Will. “I’m boasting of my investigative skills, and I would prefer to do it without interruption. Where was I?"