ROGUE ONE: A STAR WARS STORY (12A, 134 mins)

Starring: Felicity Jones, Diego Luna, Ben Mendelsohn, Donnie Yu, Mads Mikkelsen, Alan Tudyk, Jiang Wen, Forest Whitaker, Riz Ahmed, Genevieve O'Reilly and the voice of James Earl Jones. Director: Gareth Edwards.

OPENING with the familiar, luminous blue legend - "A long time ago in a galaxy far, far away..." - but not the scene-setting title crawl reserved for official episodes of the Star Wars saga, Rogue One is a rollicking, action-packed romp that dovetails neatly into the sprawling, otherworldly opus writ large by George Lucas.

The visionary filmmaker came close to self-exterminating his elegant handiwork with the abomination of Star Wars: Episode I - The Phantom Menace.

Thankfully, this prequel under the assured captaincy of director Gareth Edwards, which unfolds shortly before Episode IV - A New Hope, learns from mistakes of the past and isn't a mindless slave to technological wizardry.

Certainly, there are dazzling visual effects and breathtaking battle sequences, including cute nods to previous films in the series that will have fan boys and girls whooping with unrestrained glee.

Scriptwriters Chris Weitz and Tony Gilroy preach to the converted with lovingly recycled lines of dialogue - "I've got a bad feeling about this..." - and even repurposed old footage.

However, the Force isn't perpetually strong with Rogue One.

A disappointingly linear plot occasionally clunks and grinds like an AT-AT combat walker with a rusty knee joint, and characters' heartfelt diatribes about the corruptibility of morals in the white hot crucible of war only land glancing blows.

The Galactic Empire begins construction of a new superweapon under the command of research director Orson Krennic (Ben Mendelsohn).

If this behemoth, powered by the same Khyber crystals as light sabres, becomes fully operational, the Imperial Military will crush all resistance.

From the Rebel Alliance headquarters on Yavin 4, Mon Mothma (Genevieve O'Reilly) and other council members hastily prepare a response.

They despatch Captain Cassian Andor (Diego Luna) and a reprogrammed enforcer droid, K-2SO (Alan Tudyk), to rescue Jyn Erso (Felicity Jones) from an Imperial labour camp on Wobani, knowing she can lead them to her estranged father, Galen (Mads Mikkelsen), one of the architects of the Death Star.

Together, Jyn and Cassian must steal the design schematics to the superweapon from a heavily fortified complex on Scarif, aided by blind assassin Chirrut Imwe (Donnie Yen), his gun-toting protector Baze Malbus (Jiang Wen) and Imperial pilot defector Bodhi Rook (Riz Ahmed).

Meanwhile, Orson prepares a test of his "planet killer" to impress the Emperor and Darth Vader (voiced by James Earl Jones).

Rogue One: A Star Wars Story is a bombastic and frequently bruising rumble in the space jungle that lays bare the harsh realities of conflict for the emotionally scarred warriors on the ground.

Jones is a plucky heroine, issuing the film's central battle cry built on the unswerving belief that "rebellions are built on hope", and Luna is a solid foil in every respect.

Tudyk provides the droll comic relief as the robotic sidekick, who is hard-wired to say whatever "comes into his circuits".

Director Edwards conjures some magnificent action sequences that look spectacular in 3D, and Michael Giacchino's score nods affectionately to the stirring themes of John Williams from many moons ago.

Unlike Lucas' hellish prequels, this is a step back in time that signals a bright future. 8/10