Just when you thought Harry Dresden had every problem a wizard could have, a new one appears. 
 And his problems pile up like so many skulls in the twelfth book of the Dresden Files series, which is appropriately titled "Changes." Jim Butcher's quirky sense of humor is still in place ("Ick! My lips touched dog lips!"), but this is definitely a darker twist in the series -- and Butcher seems intent on diving down into a place that's far darker, bloodier and scarier than most urban fantasy authors can even dream of. 
 Harry is understandably shocked when his ex-girlfriend Susan tells him that their daughter has been abducted by Duchess Arianna Ortega, a vampire of the Red Court who has a personal grudge against him. After all, he didn't even know he HAD a daughter. To make matters even worse, the supernatural world is on the verge of imploding because of the Red Court's war with the White Council, which means that Harry can't depend on his own kind for any actual help. 
 And what's more, Harry's being bombarded by assassins, giant Mayan demons, and hordes of Red Court vampires out to destroy/vampirize him. He has to gather as many allies as possible before Arianna puts her lethal plan into effect, and he might have to sacrifice his morals to do so. But even then, an all-out assault on the Red Court in their own territory will tax Harry and his little fellowship to the limits -- and will tear away even more of what he loves. 
 "Changes" is a painfully appropriate name for this book. Just about everything you know in the Dresden Files series changes here -- the enemies, the allies, the politics, the devastating losses and even the war against the Red Court. Even the series itself is changing from an urban fantasy series into an EPIC fantasy series -- and it feels like a turning point after which everything (and I do mean everything) will be different. 
 For most of the book, Butcher whips up his usual mixture of action (a giant centipede out of "Inuyasha," a pitched battle in a fae court), convoluted supernatural politics, funny clothing, and pop culture references ("You know, I believe it IS possible to reference something other than "Star Wars," boss." "That is why you fail"). 
 But a bleak, dark undercurrent runs through the entire book, and it gets darker every time another little piece of Harry's life is chipped away. Butcher spends the whole book creating a slow-burning build-up to a really nasty confrontation with the Reds, and it all culminates in a truly explosive climax that's soaked in blood, magic, and the deepest passions of the human heart. Here's the only disappointing aspect of it -- the "to be continued!" cliffhanger. 
 Butcher also brings in countless characters from previous books (Thomas, Sanya, Uriel, Butters, Toot, the ever-elusive Lea, Luccio), and introduces a few new ones (Vadderung, who resembles a certain ancient father-god). But the center of this story is undeniably Harry, who is so determined to save his daughter that he is willing to do literally anything -- he's even willing to do things you would never have thought him capable of. 
 "Changes" is full of changes -- it's the ending of an era in the Dresden Files, and it leaves you desperate to know what will happen next. Utterly brilliant, and truly heartbreaking.