Ninth Key (The Mediator)

Ninth Key (The Mediator) by Carroll, Jenny. paperback edition. ISBN: 9780671787981.

"Theres no such thing as ghosts." At least, thats what the scientific community believes. High school sophomore Susannah Simon wishes she could agree. Shes only lived in sunny California for two weeks, and already her lifes a whirlwind of pool parties, excellent hair days, and new friends. Oh, yeah...and her stepbrothers. But otherwise, things are going fab. Until the ghost of a dead woman shows up at her bedside, screaming and begging Suze to find "Red" and tell him that he isnt responsible for her death. Tracking down a murderer isnt exactly easy, especially when the clues that Suze pieces together lead straight to the father of Tad Beaumont, the cutest and richest boy in school...and the first boy whos ever asked Suze out. Oops.