The Ghost and Mrs. Hobbs — Cynthia DeFelice

Just a few short weeks ago, sixth-grader Allie Nichols realized that she must be some kind of ghost magnet when she met the spirit of a murdered girl. Now, a new ghost has appeared to her, a handsome young man, and he's pointed her in the direction of her creepy cafeteria lady, Mrs. Hobbs. Allie has always suspected Mrs. Hobbs of something, and this just confirms it. So do the mysterious fires that keep breaking out every time Allie tries to investigate her. Surely Mrs. Hobbs isn't going to kill her. Or is she?