Percy Jackson & The Olympians: The Demigod Files

flowers.
    “Take care, huntress,” Persephone warned. “Your father may be Zeus, and you may be the lieutenant of Artemis, but you do not speak to me with disrespect in my own palace.”
    Thalia ground her teeth. “Give . . . me . . . back . . . my . . . bow.”
    Persephone waved her hand. The bow and arrows changed back to normal. “Now, sit and listen. The sword could not have left the Underworld yet. Lord Hades used his remaining keys to shut down the realm. Nothing gets in or out until he finds the sword, and he is using all his power to locate the thief.”
    Thalia sat down reluctantly. “Then what do you need us for?”
    “The search for the blade cannot be common knowledge,” said the goddess. “We have locked the realm, but we have not announced why, nor can Hades’s servants be used for the search. They cannot know the blade exists until it is finished. Certainly they can’t know it is missing.”
    “If they thought Hades was in trouble, they might desert him,” Nico guessed. “And join the Titans.”
    Persephone didn’t answer, but if a goddess can look nervous, she did. “The thief must be a demigod. No immortal can steal another immortal’s weapon directly. Even Kronos must abide by that Ancient Law. He has a champion down here somewhere. And to catch a demigod . . . we shall use three.”
    “Why us?” I said.
    “You are the children of the three major gods,” Persephone said. “Who could withstand your combined power? Besides, when you restore the sword to Hades, you will send a message to Olympus. Zeus and Poseidon will not protest Hades’s new weapon if it is given to him by their own children. It will show that you trust Hades.”
    “But I don’t trust him,” Thalia said.
    “Ditto,” I said. “Why should we do anything for Hades, much less give him a superweapon? Right, Nico?”
    Nico stared at the table. His fingers tapped on his black Stygian blade.
    “Right, Nico?” I prompted.
    It took him a second to focus on me. “I have to do this, Percy. He’s my father.”
    “Oh, no way,” Thalia protested. “You can’t believe this is a good idea!”
    “Would you rather have the sword in Kronos’s hands?” He had a point there.
    “Time is wasting,” Persephone said. “The thief may have accomplices in the Underworld, and he will be looking for a way out.”
    I frowned. “I thought you said the realm was locked.”
    “No prison is airtight, not even the Underworld. Souls are always finding new ways out faster than Hades can close them. You must retrieve the sword before it leaves our realm, or all is lost.”
    “Even if we wanted to,” Thalia said, “how would we find this thief?”
    A potted plant appeared on the table: a sickly yellow carnation with a few green leaves. The flower listed sideways, as if it were trying to find the sun.
    “This will guide you,” the goddess said.
    “A magic carnation?” I asked.
    “The flower always faces the thief. As your prey gets closer to escaping, the petals will fall off.”
    Right on cue, a yellow petal turned gray and fluttered into the dirt.
    “If all the petals fall off,” Persephone said, “the flower dies. This means the thief has reached an exit and you have failed.”
    I glanced at Thalia. She didn’t seem too enthusiastic about the whole track-a-thief-with-a-flower thing. Then I looked at Nico. Unfortunately, I recognized the expression on his face. I knew what it was like wanting to make your dad proud, even if your dad was hard to love. In this case, really hard to love.
    Nico was going to do this, with or without us. And I couldn’t let him go alone.
    “One condition,” I told Persephone. “Hades will have to swear on the River Styx that he will never use this sword against the gods.”
    The goddess shrugged. “I am not Lord Hades, but I am confident he would do this—as payment for your help.”
    Another petal fell off the carnation.
    I turned to Thalia. “I’ll hold the flower while you beat up the thief ?”
    She sighed. “Fine. Let’s go catch this jerk.”
    The Underworld didn’t get into the Christmas spirit. As we made our way down the palace road into the Fields of Asphodel, it looked pretty much like it had on my previous visit—seriously depressing. Yellow grass and stunted black poplar trees rolled on forever. Shades drifted aimlessly across the hills, coming from nowhere and going nowhere, chattering to each other and trying to remember who they were in life. High above us, the