Not a lot of writers would be brave enough to pen a love story between a girl-turned-old-lady and a wizard missing a vital organ. 
 But fantasy dowager Diana Wynne Jones was one of those brave enough to write such a story -- and not only does she succeed, but she creates a brilliantly charming story. It's crammed with complex magical conspiracies, unlikely heroines, dimension-hopping, curse and contracts, and some sly subversions of the usual fairy tale tropes (such as good things only happening to the youngest). 
 A misunderstanding leads to ordinary Sophie Hatter being turned into a crone by the malevolent Witch of the Waste. Finding old age oddly liberating, she wanders away from her hat shop, and becomes the cleaning lady for the powerful wizard Howl, who lives in a moving castle with his fire demon Calcifer. Calcifer strikes a deal with Sophie -- if she can break the contract between him and Howl, he'll restore her youth. The catch is, neither he nor Howl can tell her WHAT the contract is. 
 While assisting Howl and his apprentice Michael, Sophie discovers that Howl's reputation for wickedness is rather exaggerated -- he doesn't actually eat girls' hearts and suck out their souls, but he is a prodigious flirt who abandons girls once he gets them to fall for him. He's also kind of a drama queen. But soon Sophie finds that the powerful wizard is ensnared in a horrifying curse -- and Howl has only a little time before the curse strikes. 
 One of Diana Wynne Jones' favorite sources of humor was poking fun at the tropes of fantasy and fairy tales. If you've ever read a fairy tale -- "Cinderella," "Beauty and the Beast" -- you'll know that the youngest kids are always the pure-hearted ones destined for great things. So Jones obviously had a lot of fun with this idea, and uses it as the jumping-off point for "Howl's Moving Castle." 
 Along the way, she peppers her novel with a complicated, intertwined conspiracy that Sophie only discovers as she spends more time with Howl, involving a curse (""Go and catch a falling star/Get with child a mandrake root..."), a lost prince, and the Witch of the Waste. The curse's slow unveiling creates a growing sense of dread without revealing much, except the awareness that something terrible is rising slowly. 
 But it's handled in a fun, tongue-in-cheek way, with Sophie having to deal with Howl's immaturity (he has a green slime attack when his hair is dyed ginger) as well as the woes associated with magic (the seven-league boots). And Jones clearly had some fun throwing odd twists into the mix. 
 Sophie is a rather timid, dull character until her unexpected aging sets her free from her unhappy life. Her sensible, assertive new self is a pretty entertaining heroine, especially as she starts feeling both exasperation and romantic interest in Howl. Howl is a delightful character -- he's fickle, immature, flamboyant, eccentric, irresponsible and has cultivated a distinct image as a wicked, heart-devouring sorcerer to keep everyone far away from him. And yet, he's oddly charming and fun to read about, especially as a foil to the sensible Sophie. 
 Moving castles, fire demons and an oddly charming wizard make "Howl's Moving Castle" an absolute must-read -- especially for those who like their complicated fantasies to be a little tongue-in-cheek.