The closer Harry gets to the climax of the Potter series, the longer the novel. This creates bigger and bigger problems for Steve Kloves, the go-to man when it comes to Potter adaptations. 

Whole storylines and subplots are jettisoned in order to keep the already-burgeoning running times to a minimum as others are ramped up in order to create a new dynamic to the story.

While Kloves has had his moments, Half Blood Prince is one of his most successful adaptations to date, albeit clocking in at over two-and-a-half-hours.

Teenage angst is the order of the day at Hogwarts as the kids look upon each other in a whole new light. If the opening movies were in the tone of Chris Columbus's family fare, then the latest are more like 90210 Meets Sabrinia The Teenage Witch: The Movie.

It's been just a few weeks since Harry witnessed the demise of his godfather, Sirius Black, and he's wishing away the summer months whilst traveling on random trains. Soon enough Professor Dumbledore (Gambon) comes calling, taking Harry on a trip to meet Horace Slughorn (Broadbent), a teacher Dumbledore wishes to tempt back to Hogwarts.

For Slughorn not only taught generations of wizards, including Harry's parents, but he also holds the key to killing Lord Voldemort once and for all. If only Dumbledore would tell Harry what that key is...

Meanwhile, Severus Snape (Rickman) appears to have shown his true colours during a meeting with Bellatrix LeStrange (Bonham Carter) - Black's murderer - in which he swears to protect Harry's enemy, Draco Malfoy (Tom Felton), who has been charged with a very important, and very deadly, job.

Despite being an inexperienced television director, Yates has a stronger grasp of what makes a good Potter movie than his vastly experienced predecessors. Less hung up about the particulars of the school year, Yates knows what makes a Potter movie work and happily cuts out anything that gets in the way, all the while blending special effects with the story rather than slapping them on top.

The rapidly improving young cast continues to shine - Harry's tongue-in-cheek claim to be 'the chosen one' is delivered wth true comic timing for a change - as do the likes of the ever-reliable Rickman and Gambon, and of course Bonham Carter, but it's Jim Broadbent who steals the show, somehow creating a standout character in Horace Slughorn, despite existing in an already crowded realm.

It's certainly long - although fans won't be too miffed - and, for some, the teen drama might not hold the attention between the plotline that makes up the (hor)crux of the story.

And then there's THAT ending, in which battle lines are drawn, climaxes set up and tears shed.

Harry Potter rarely holds a candle to The Lord Of The Rings, but the closer the boy wizard gets to realising his destiny, the more confident the filmmaking. If the two-part finale continues on this trajectory, then the best is yet to come.

Rich Phippen