One for Sorrow by Zoe Sugg and Amy McCulloch

Illumen Hall is an elite boarding school. Tragedy strikes when the body of a student is discovered at their exclusive summer party – on her back is an elaborate tattoo of a magpie. When new girl Audrey arrives the following term, running from her own secrets back home in America, she is thrown into solving the case. Despite her best efforts to avoid any drama, her new roommate Ivy was close to the murdered girl, and the two of them can’t help but get pulled in… Read more.