In this mystery in the New York Times bestselling Cat in the Stacks series, librarian Charlie Harris and his cat Diesel must clear the name of someone near and dear to their hearts—Charlie’s own daughter.

Athena College’s new writer in residence is a famous native son, playwright Connor Lawton, known for his sharp writing—and sharper tongue. After an unpleasant encounter, librarian Charlie Harris heads home to a nice surprise: his daughter, Laura, is visiting and will be subbing for another professor this fall semester. It’s great news until he hears who got her the job: her old flame, Connor Lawton...

Fearing competition for Connor’s affections, one of his admirers tries to drive Laura out of town. And then, before Connor finishes the play he is writing, he is murdered—and Laura is the prime suspect. Knowing she’s innocent, Charlie and his faithful sidekick, Diesel, follow Connor’s cluttered trail of angry lovers, bitter enemies, and intriguing library research to find the true killer before his daughter is forever cataloged under “M”—for murderer.