I've written an awful lot of books. There are eleven for middle-aged children, mostly fantasies. The ones that have hung around the longest are "The Diamond in the Window" and "The Fledgling." The seventh in the series called "The Hall Family Chronicles" came out last spring, "The Mysterious Circus," and I've just finished writing an eighth, "The Dragon Tree." All eighteen mysteries for adults have the same protagonists, Homer and Mary Kelly. Mary is the sensible one, but I confess I like Homer's rhapsodic flights of fancy. Most of their adventures happen in Massachusetts, but I've also sent them to farflung places I wanted to visit myself, like Florence, Oxford and Venice. Most of the novels are illustrated with my own drawings, but "The Escher Twist" has ten prints by the mysterious Dutch artist M. C. Escher, and the two historical mysteries are illustrated with nineteenth-century photographs.