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.

I found that things weren't going well upstairs. Carter was a crumpled heap of chicken warrior on the slope of the pyramid.

"Anybody have money?" Frank checked his pockets. "Three denarii from Camp Jupiter. Five dollars Canadian." Hedge patted his gym shorts and pulled out what he found. "Three quarters, two dimes, a rubber band and - score! A piece of celery." He started munching on the celery, eyeing the change and the rubber band like they might be next.

She whirled when the monster was almost on top of her. I thought the thing in her hands was an umbrella until she cranked the pump and the shotgun blast blew the giant twenty feet backwards, right into Nico's sword. "Nice one," Paul said. "When did you learn to fire a shotgun?" I demanded. My mom blew the hair out of her face. "About two seconds ago. Percy, we'll be fine. Go!

Before I could lose my courage, I said, "Don't I get a kiss for luck? It's kind of a tradition, right?" I figured she would punch me. Instead, she drew her knife and stared at the army marching toward us. "Come back alive, Seaweed Brain. Then, we'll see.

When I write, I'm still imagining a kid reading it on paper. I read e-books when I travel, but in general I still prefer holding an old-fashioned book in my hands. There's a special, tactile experience.

That's great. Except for the fact that it's completely unimportant.