TWO STARS

The third film in the Riddick series, which began in 2000 with the muscular sci-fi thriller Pitch Black, is the least unsatisfying chapter of the ongoing saga.

Made at a fraction of the price of the overblown 2004 sequel The Chronicles Of Riddick, this new instalment pares back the pyrotechnics, focusing on the lead character as he adjusts to hazardous surroundings.

Writer-director David Twohy even throws in a canine sidekick to humanise his hulking killing machine and provide us with moments of obvious humour.

Vin Diesel reprises his role as the visually impaired “zulu warlock” with unabashed gusto, flinging himself into the various action sequences that Twohy uses to punctuate his flaccid storyline. In one of the film’s many risible moments, the leading man strips off and clambers up a rocky formation and stares into the sky, his rippling frame bathed in the light of an alien moon. If all else fails, frighten off the enemy with gratuitous nudity.

Riddick (Diesel) has been left for dead on a sun-scorched planet, which seems to be lifeless. The mercenary quickly discovers there is alien life on this outpost and he cannot battle the predators forever.

Riddick’s only hope is to activate an emergency beacon and steal aboard a rescue ship. The beacon alerts bounty hunters to his position and they descend on the planet determined to kill Riddick and collect their fee. Santana (Molla) and his men are the first to answer the distress signal and they set up sensors around their craft to track Riddick’s movements.

A rival squad led by Boss Johns (Nable) and his sassy sidekick Dahl (Sackhoff) arrive next but they have a slightly different agenda for wanting to track down Riddick.

Santana tries to assert his authority over Boss Johns — “As soon as I have his head in a box, I will let you know!” — but infighting between the bounty hunters allows Riddick time to sneak up on his hunters.

And time is of the essence because a deadly storm is coming to sweep across the planet’s surface, killing everyone in its path.

Riddick doesn’t advance the central character’s storyline at all and the two hours drag. Diesel can growl Twohy’s dialogue in his sleep, and since his character wears darkened goggles for a while, maybe he does, considering the emotion in his delivery.

Supporting cast inhabit their unwritten roles with sweat-drenched purpose while special effects vary wildly in quality: some digital characters don’t meld seamlessly with live action backgrounds.

From beginning to end, Twohy’s film is riddickulous but fans of earlier films will probably love every grunt and groan.