An earnest 13th-century wizard follows his pet dragon through a time/space bolt-hole into contemporary Boston in this lightweight, pleasant fantasy. While Gideon negotiates modern technology and city life (luckily befriended by a convenient Harvard wizard), Wycca the dragon lays her egg in a Boston tower and becomes addicted to chocolate. Also involved are Theodora, a Cambridge girl having a boring summer, and Kobold, another 13th-century wizard who is evil. Local readers may wonder why some Cambridge details are true while others aren’t, but fans of wizard and dragon paraphernalia will hope that their fantasies come as true as Theodora’s: an ancient wyvern card sticks to her shoe in the street and brings her the newly hatched wyvern to save. Potions and spells abound, but the narrative is over-obvious, leaving too little for readers to figure out. However, the pace quickens near the end, and several delightful closing details produce a satisfying finish. (Fiction. 8-11)