Young Lucy Pennykettle is absolutely convinced that a terrifying monster is lurking outside her bedroom window in the dark. She is too scared to sleep, but her mother knows exactly how to handle the situation. Mixing a tiny bit of magic with her special clay, she creates Gruffen, a brave little miniature guard dragon brought to life specifically to protect Lucy's room. As the tiny dragon bravely stands watch over the window, he makes a highly unexpected discovery. The scary monster is not a monster at all, but rather a friendly little bat named Hattie! Hattie is in desperate need of help because the grumpy next door neighbor, Mr. Henry Bacon, has cruelly boarded up her home, leaving her and her baby batlings with nowhere to go. Realizing they have a shared enemy, Gruffen and Hattie quickly become the best of friends. Together, this tiny dragon and clever bat must hatch a brilliant plan to outsmart the mean neighbor and find a safe, warm new home for the bat family.