When an art exhibition comes to the library, it's up to Kathleen to deal with all the hassle that comes with it, mainly in the form of people: the overworked and exasperated curator, the too-charming security expert and the owners of the valuable historical sketch that is the centrepiece of the show. But when the curator turns up dead in Kathleen's office and the valuable sketch vanishes, her magical cats Owen and Hercules have to turn to the art section of their detection skills to help Kathleen solve the murder.