Rachel is the oracle since The Last Olympian. She was in love with Percy until she became an oracle and saw her true purpose. She'd been drawn to a demigod because of his mythical origin. During Saturn's attack on New York, she was a mortal who didn't fall asleep after Hypnos- god of sleep- placed a curse over Manhattan. She was first seen in The Titan's Curse at the Hoover Dam and helped save Percy from zombie skeleton type creatures specially grown by the General. She also has 'true sight' which means the Mist does not veil what's happening in real world situations versus what mortals want to believe. Sally Jackson also has 'true sight'. In The House of Hades, she and Grover met the Romans in terms of a peace talk by request of Reyna.