Colleen’s of Medford Square presents a pop-up event featuring Medford’s Wendy Pfaffenbach, author of the children’s book “The Fells Fairies.” In the book, the Middlesex Fells nature preserve is in danger. Developers want to take it over and build a shopping mall. The Fairy Queen has called upon two little girls, Star and Bird, to save the forest. Can they come up with a plan to stop the destruction? Books will be available for purchase and signing by the author.