NOT since Harry Potter first cast a spell over cinema audiences has a franchise based on a series of best-selling novels been as completely critic-proof as The Twilight Saga.

The good-looking cast could probably stare silently into the camera for two hours and fans of Stephenie Meyer’s teen romances would still flock to the multiplexes in their millions.

Thankfully, Chris Weitz’s eagerly anticipated rendering of the second instalment of the four-book saga is thoroughly entertaining and more polished than its predecessor.

Hunky male leads Robert Pattinson and Taylor Lautner spend an inordinate amount of time with their shirts off, the latter sporting a washboard chest and abs that must have taken hours of work in a gym.

New Moon is too long – 15 minutes of gloom and adolescent angst could easily have been excised from the opening act – but it’s unlikely that the target audience will complain.

Screenwriter Melissa Rosenberg sensibly spends the entire middle act establishing the love triangle that sustains not just this film but also the next, Eclipse, which is due in cinemas in July 2010.

This is soap opera writ large, complete with a cliffhanger finale that leaves the audience teetering on the edge of their seats until next summer.

The love affair between teenage misfit Bella Swan (Kristen Stewart) and vampire Edward Cullen (Pattinson) reaches a crossroads, and the paths ahead all lead to heartbreak.

Edward and the Cullen clan – Dr Carlisle (Peter Facinelli), Esme (Elizabeth Reaser), Alice (Ashley Greene), Jasper (Jackson Rathbone), Emmett (Kellan Lutz) and Rosalie (Nikki Reed) – are forced to abandon the close-knit community of Forks, Washington, if Bella is ever to be safe.

“You just don’t belong in my world,” Edward tells his beloved.

Abandoned by her soul(less) mate, the teenager becomes a shadow of her former self until her relationship with buffed-up family friend Jacob Black (Taylor Lautner) takes an exciting, new turn.

Bloodthirsty predator Laurent (Ed Gathegi) returns to deal Bella a fatal blow at the behest of vengeful Victoria (Rachelle Lefevre) but a new protector is there in the girl’s hour of need.

The Twilight Saga: New Moon is glossy froth but it’s extremely well made, apart from some of the digitally generated werewolves.

The slavering carnivores lack the correct inertia and momentum, notably in a pivotal chase sequence.

Weitz certainly likes his musical montages employing them almost back-to-back in the opening hour, but like everything else in the film, they are polished to a sheen.

Stewart teases out her heroine’s internal anguish as Bella finds herself torn between morose Edward and hot-blooded Jacob.

“I’m not like a car you can fix up. I’m never gonna run right,” she tells the Quileute tribe member, in a half-hearted attempt to ward him off.

Romantic scenes with Lautner smolder just as much as with Pattinson, which bodes well for the next film.

• Showing at the Empire and ABC