“But Philippa was hardly listening. "It's a riddle," she declared finally, pointing to the card in the strange little round window. "I think that if we answer the riddle we can get in. Listen 'The beginning of eternity. The end of time and space. The beginning of every end. And the end pf everyplace." John shrugged. "I don't get it." "No, but I do," Philippa said triumphantly. "The answer is the letter e. E is the beginning of eternity, the end of time and space, the beginning of every end, and the end of everyplace.”