Played out on a vast -- at times overpopulated -- canvas, Harry Potter and the Half-Blood Prince  is a richly textured adventure in which good and evil are clearly portrayed, but characters present a range of moral shading.

At the command of his mentor (Michael Gambon), the now-teenage Harry Potter (Daniel Radcliffe) attracts himself with a returning Hogwarts instructor Horace Slughorn (Jim Broadbent) who once taught his archenemy Lord Voldemort and whose memories may hold the key to defeating the villain, while adolescent romantic tensions complicate the lad's relationship with his two closest friends (Rupert Grint and Emma Watson). As directed by David Yates, this sixth adaptation of J.K. Rowling's hugely popular fantasy novel series is a richly textured, though at times overcrowded, adventure narrative in which good and evil are clearly delineated, but characters present a range of moral shading.

As they did in the franchise's earlier films, magical elements in this sixth adaptation of J.K. Rowling's immensely popular fantasy novel series serve merely as props in a study of loyalty, friendship and the varied human responses to temptation. The basis of the story continues to be the struggle between a now-teenage Harry and the forces of darkness known as the Death Eaters whose leader, Lord Voldemort, murdered Harry's parents while he was still an infant.

Harry's key student rival, Draco Malfoy (Tom Fenton), is motivated by jealousy of Harry's prophesied status as the "Chosen One" -- to act as Voldemort's agent within Hogwarts, though a scene in which he breaks down in sobs while alone shows the strain this alliance causes him, and suggests that he could also be capable of better things.

Temptation comes Harry's way when he discovers a series of secret notes in his worn copy of the school's potions textbook made by a long-ago student who signed himself the Half-Blood Prince. While these markings originally prove helpful, they turn out to include devastating curses that could draw Harry across the moral divide.

Both Slughorn and Hogwarts' newly installed teacher of Defense Against the Dark Arts, Severus Snape (Alan Rickman), seem ambiguous, if not downright suspicious. Slughorn's Broadbent is brilliant but overly status-conscious, and none too anxious to reveal his dealings with Riddle, while the masterful Snape has a sarcastic tone as black as his usual clothing. Interwoven with the main plot is the story of the toll adolescent romantic agitations are taking on Harry's long-standing friendship with Hermione and Ron.

While slow at parts, and an extremely dark film, the film is enjoyable a great deal. Certainly, it is far from impeccable, but it was entertaining and well done, with appropriate opening and closing. Harry Potter and the Half-Blood Prince is a film that addresses issues worth delivering, growing to maturity chiefly among those. The series will prove certain critics wrong, and impress open-minded individuals.