billion worldwide, the filmmakers strike a pitch-perfect balance of faithfulness to the J.K. Rowling novel without being too oblique for neophytes. This marks the second "Potter" outing for veteran British TV director David Yates (having also helmed 2007's "Harry Potter and the Order of the Phoenix"), and here, he displays an impressive surefootedness with the dynamics of a ginormously successful franchise that, by any standard, must be daunting.

In "Half-Blood Prince," Harry Potter (Daniel Radcliffe) and his chums, Ron Weasley (Rupert Grint) and Hermione Granger (Emma Watson), are now teenagers subject to the same hormone-addled dramas that plague their Muggle counterparts. Love is in the air at the Hogwarts School of Witchcraft and Wizardry, which means rivalries, heartaches and the generous use of love potions. Harry is increasingly drawn to Ron's younger sister, Ginny (Bonnie Wright), but she already has a boyfriend. Hermione pines away for Ron, but he can barely see past the smothering of Lavender Brown (Jessie Cave). Consider it Hogwarts meets John Hughes. Even headmaster Albus Dumbledore (Michael Gambon) takes note of the soap operatics, musing, "To be young and feel love's keen sting."

KEY MEMORY
If "Half-Blood Prince" occasionally has the familiar, if not unwelcome, ring of a high school romantic comedy, rest assured that more ominous goings-on are close at hand. Early on, Dumbledore persuades Hogwarts' former professor of potions, Horace Slughorn (Jim Broadbent, "Indiana Jones and the Kingdom of the Crystal Skull"), to resume teaching at the school. The headmaster then recruits Harry to buddy up to the somewhat daft professor and help uncover a key memory of Slughorn's that involves ex-pupil Tom Riddle (Hero Fiennes-Tifflin and Frank Dillane, at different ages), a boy who grew up to become none other than Lord Voldemort.

While the dreaded dark lord doesn't appear in "Half-Blood Prince," there is still plenty of trouble. A trio of Death Eaters led by Bellatrix Lestrange (Helena Bonham Carter, "Terminator: Salvation") is on a spree of destruction throughout the Muggle and magic worlds. Harry's longtime school yard nemesis, Draco Malfoy (Tom Felton), is acting even creepier than usual. Last but not least is a mystery surrounding Harry's discovery of an old magic textbook full of spells and potions by the self-proclaimed "half-blood prince."

The young leads have literally grown into their roles since the franchise launched in 2001 with "Harry Potter and the Sorcerer's Stone," and that familiarity "” both theirs and the audience's "” adds depth to the characters. Radcliffe has the thankless task of being a somewhat passive hero, but he's likable enough. Watson reveals vulnerability as the lovelorn Hermione, while Grint gets to display a knack for comedy. Of course, these films always benefit from some of Britain's finest thespians, with Gambon, Broadbent, Alan Rickman and Maggie Smith as particular standouts.

The cast even manages to avoid being upstaged by truly dazzling special effects. While the second "Transformers" flick demonstrates the bludgeoning potential of CGI, Yates and his extraordinary cinematographer, Bruce Delbonnel ("Across the Universe," "Am