*Dr. Sophie Knowles loves using puzzles to make math fun for students. But when winter seizes Henley College, she must thaw out a cold case to track down a killer—her most difficult puzzle yet . . . *

Winter Intersession is in full swing, and campus is buzzing over the concert celebrating the bell tower’s reopening. The building has been shuttered for twenty-five years, and Sophie’s shocked to learn why—a student leapt from it to her death. But she’s even more troubled by the secrecy surrounding the case. After Sophie performs some quick calculations, she’s left with a nagging question: Was it really suicide?

When one of Sophie’s favorite students, a performer in the concert, is brutally beaten and left in a coma, Sophie’s mind kicks into overdrive. The horrific incidents seem too coincidental to be unrelated, but can Sophie put together the pieces from a twenty-five-year-old murder before any other students get hurt?

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