As Annabeth sat on the hill, tucked under Percy's arm, an explosion sounded in the distance. She jumped to her feet, her boyfriend right beside her.
'What was that?' she exclaimed.
'Come on!' Percy took off, running down the hill to the camp.
Annabeth followed, wondering what had happened. Surely it could't be another Roman attack- and the Greeks were under strict orders not to retaliate. Another bang sounded, and another. They appeared to be getting closer.
At the bottom of the hill, Clarisse was shrieking orders in all directions. Annabeth reached the foot of the hill, pulling up next to Percy. A huge boom sounded, shaking the earth. A few tiles fell from the roof of the Big House, but apart from that, no visible damage had occurred.
What was going on?