Rowling proves that she has plenty of tricks left up her sleeve in this third Harry Potter adventure, set once again at the Hogwarts School for Witchcraft and Wizardry. Right before the start of term, a supremely dangerous criminal breaks out of a supposedly impregnable wizards' prison; it will come as no surprise to Potter fans that the villain, a henchman of Harry's old enemy Lord Voldemort, appears to have targeted Harry. In many ways this installment seems to serve a transitional role in the seven-volume series: while many of the adventures are breathlessly relayed, they appear to be laying groundwork for even more exciting adventures to come. The beauty here lies in the genius of Rowling's plotting. Seemingly minor details established in books one and two unfold to take on unforeseen significance, and the finale, while not airtight in its internal logic, is utterly thrilling. Rowling's wit never flags, whether constructing the workings of the wizard world (Just how would a magician be made to stay behind bars?) or tossing off quick jokes (a grandmother wears a hat decorated with a stuffed vulture; the divination classroom looks like a tawdry tea shop). The Potter spell is holding strong.