I'm stupid," Leo mumbled. "Pi would expand outward, because it's infinite." He reversed the order of the numbers, starting in the center and working toward the edge. When he aligned the last ring, something inside the sphere clicked. The door swung open. Leo beamed at his friends. "That, good people, is how we do things in Leo World. Come on in!" "I hate Leo World," Frank muttered. Hazel laughed.
Rick RiordanNico strode forward. The enemy army fell back before him like he radiated death, which of course he did. Through the face guard of his skull-shaped helmet, he smiled. "Got your message. Is it too late to join the party?" "Son of Hades." Kronos spit on the ground. "Do you love death so much you wish to experience it?" "Your death," Nico said, "would be great for me." "I'm immortal, you fool! I have escaped Tartarus. You have no business here, and no chance to live." Nico drew his sword-three feet of wicked sharp Stygian iron, black as a nightmare. "I don't agree.
Rick Riordan