The Scarlet Letterman by Cara Lockwood
Miranda is back for her second semester at Bard. She's got the ghost faculty in her debt, a new boyfriend (Ryan Kent), and even an A in English. But just when she thinks everything is finally starting to go her way, faculty start disappearing and Headmaster Bronte begins to suspect that Miranda is involved. To make matters worse, Miranda discovers new and disturbing rumors about her new boyfriend, speculating that he may have caused his ex-girlfriend's death. Are the rumors true? Or are they just planted by a jealous Parker Rodham (the school Queen Bee and Bully)? Miranda has to solve the mystery of her boyfriend's ex and try to save the faculty, all while trying to pass her spring finals.