"*Starred Review* Rowling follows basically the same formula in each Harry Potter book, all the while maintaining the same high levels of freshness and quality. Here Harry, along with his sidekicks Ron and Hermione, once again faces great danger. It's become known that the infamous murderer Sirus Black has broken out of the supposedly escape-proof Azkaban fortress and is after Harry. Hence, Harry finds himself restricted to the Hogwarts campus, where everyone can keep an eye on him. Not one to let things like this stand in his way, Harry, with the help of his Invisibility Cape, manages to get into town and into trouble. Harry also finds himself beset by his usual school nemeses, Malfoy and his cronies, as well as Professor Snape, who seems to hate Harry even more than before. Rowling stirs all this together and leavens it with the now-expected generous helping of humor. Add to this the dementors, who ""are among the foulest creatures that walk this earth,"" draining peace, hope, and happiness out of humans; a werewolf, who teaches Defense Against the Dark Arts; a magical map; and a bit of time travel. What results once again is a good story well told, one that is not only a cut above most fantasies for the age group but is also attractive to readers from beyond both ends of the spectrum. The Harry Potter books have the same sense of continuity found in Brian Jacques' popular Redwall saga--with villains, heroes, schemers, and innocents all firmly in their places, the seemingly impossible solved, and good triumphing over evil. And we wait impatiently for the next episode. (Reviewed September 1, 1999)"