The newest book in the Harry Potter series -- "Harry Potter and the Half-Blood Prince" -- goes on sale at midnight Friday. As usual, the book's plot has been carefully kept secret from mere Muggles but never fear -- the Page 2 spies obtained an advance copy. As the following chapter shows, the Hogwarts student wizards are another year older and beginning to show interest in more adult pastimes. …Hermione lit the votive candles on her night stand, followed by a stick of incense. She turned off the light, turned up the R&B music and turned toward Harry. She removed...