Chasing Shadows — Valerie Sherrard

At last, Shelby Belgarden has put her crime-solving behind her and has returned to the life of an ordinary teenager. Now 16, she has taken her first job: working at a new local restaurant called The Steak Place. But when one of her co-workers -- a waitress named Nadine -- goes missing, Shelby suspects foul play. The police won't believe her. Neither will Shelby's boyfriend, Greg, who grows frustrated with her search for a criminal who may not exist.