The concluding chapter of the outlandish fang-tasy series based on Stephenie Meyer’s best-selling books delivers a master class in constructing CGI mountains out of molehills.

The Twilight Saga: Treading Water would be more apt, considering how scriptwriter Melissa Rosenberg manages to expand 30 minutes of plot into two hours of anticipation and dread.

A climactic battle royale between the diabolical Volturi and the Cullens is certainly spectacular and director Bill Condon, who also helmed Part 1, orchestrates this special effects-heavy mayhem with verve.

Airborne vampires and snarling werewolves tumble acrobatically across the screen while locked in mortal combat, their desperate struggles ended with a sickening snap of a neck or crude decapitation.

Were these brave warriors anything but otherworldly creatures, which miraculously don’t bleed when injured, the relentless on-screen carnage would merit a 15 certificate.

Before all of the slavering jaws and severed limbs, the fifth instalment in the series doesn’t justify the decision by film-makers to cleave Meyer’s final book in two a la Harry Potter.

Substance is woefully lacking and there are only so many slow-motion smooches that can paper over the cracks before the most ardent members of Team Edward and Team Jacob will start to look at their watches.

DAMON SMITH