Book excerpt: Math Professor Sophie Knowles shares her teaching venue with many other math and science faculty, most of whom she gets along with. But one in particular gives Sophie and her teaching assistant, Rachel, a hard time, thus annoying both women. When this colleague, a professor of chemistry, is found dead, poisoned in his office, Rachel is the prime suspect. It’s up to Sophie to put her talent for designing and solving puzzles to use to find his killer.