Books with title Poison Pen: Poppy Field's Bk 7

This title is seventh in the brilliantly addictive series of murder mysteries by an acclaimed and popular writer. It's Book Week, and Poppy and Graham are helping out at their local literacy festival. However, when the authors start getting anonymous notes featuring cartoons of themselves suffering grisly deaths, the intrepid pair realize that the world of children's books is murkier than they could ever have imagined. They'll have to move quickly to discover who's at the bottom of it - before fiction turns into fact...