Deltora Quest #7: The Valley of the Lost by Emily Rodda

seemed simple until Barda worked it out.And all because he remembered his days as a palace guard, thought Lief, writing a D above the third dash on his paper.
    Barda watched with satisfaction. “Two letters filled in!” he said. “Now — shall we face the creatures?”

G ently, they opened the bedroom door once more. The Guardian had not moved, but now the monsters were sprawled all over him. Hearing intruders, all of them raised their heads and snarled threateningly.
    “This is impossible!” breathed Barda. “They will not let us near him. How can we find out about them from here?”
    “Perhaps we can call them by name,” Jasmine suggested. “Each in turn.”
    “Well, do not call Greed first, that is all I ask,” murmured Lief.
    “Why?” Jasmine asked.
    Lief grew very still. He had spoken without thinking. He had blurted out the half-joking request because of something he had not realized he knew.
    “Because,” he said, his heart starting to pound,“because, when we first came to the palace the Guardian told us that the envious monster and the proud one are both afraid of Greed. So Greed cannot be the envious one, or the proud one, itself. And we also know that Greed is not greedy, for none of the monsters has the fault after which it has been named. So — that means Greed must be the most dangerous one of all, the one full of hatred.”
    He could tell that his friends were thinking of other things the Guardian had said. Things that at the time they had not guessed were important. But which, now, suddenly seemed very important indeed.
    Without a word, they backed out of the door for a second time, and closed it behind them.
    “He gave us the clues, and we did not realize!” hissed Jasmine. “What else did he say?”
    “He said that Envy once nearly killed the greedy one, fighting over scraps from the table,” said Barda firmly.
    “If Envy tried to kill the greedy one, then it is not greedy itself,” said Lief. “And it is not envious, we know that …”
    “And it is not full of hatred!” exclaimed Jasmine. “For we have already decided that Greed is that. So Envy … must be the one who is proud!”
    They were walking away from the door, through to another room. By now they were sure that they had no need to face the monsters. They already knew enough to work the puzzle out for themselves.
    “What else did the Guardian tell us?” hissed Lief, racking his brains. “He said …”
    “He said that Hate is not envious!” said Jasmine triumphantly. “He said it when we first saw the beasts.”
    “Yes!” Lief remembered. “And Hate is not full of hatred. And it is not proud, for Envy is the proud one. So — Hate must be greedy!”
    “And that leaves only one fault for Pride,” said Barda slowly. “Pride is envious.”
    Without a word, Lief wrote E on the first dash on his paper.
    And now there was only one letter left to find, for the rhyme had said that the second and last letters of the name were the same. Barda repeated the clue:
    My second and my last begin
    The sum of errors in the twin …
    “I have not the smallest idea what this could mean,” Jasmine confessed. “I feel I am stupid, but —”
    “If you are stupid, then so am I,” growled Barda. “It has been a mystery to me from the start.”
    And Lief could not think what the strange lines could possibly mean, either. All he knew was that somewhere in this glass-walled maze was the last clue, and they had to find it.
    Filled with desperate energy, they hurried from room to gleaming room, searching everywhere for some sign that would help them solve the riddle. But they found nothing. Nothing but magnificent emptiness.
    Finally they turned a corner and Jasmine groaned. “But we have been here before!” she exclaimed. “We have already searched this room.”
    Lief and Barda looked around them and realized that Jasmine was right.
    “There is nowhere left to look!” Barda’s face was lined with weariness, heavy with