The Question and Answer section for The Lightning Thief is a great resource to ask questions, find answers, and discuss the novel.
Percy must travel to the underworld across land because it is located in Los Angeles. He can't fly to Los Angeles because Zeus controls travel in the skies.
A. She’s been waiting for the opportunity.
A description of the clouds is difficult without know which section of the text your question pertains to. Below you will find three quotes I was able to find in the book.
From the text:
Overhead, a huge storm was brewing, with clouds blacker...
