Plenty of sound and fury, signifying nothing

OPTIMUS Prime (voiced by Peter Cullen), noble leader of the Autobot robots, is gone, leaving Humans and Transformers at war in Transformers: The Last Knight. The key to saving the future lies in understanding why the giant mechanical aliens keep arriving.

Yes, do please tell me why they persist in coming, these obnoxious multi-budget live-action sci-fi special-effects movies based on Hasbro's 1980s Transformers toy line.

Michael Bay is the series executive producer-cum-director although the fanboys are as much to blame by encouraging him with US$3.7 billion of combined ticket sales for his bash-a-thons: Transformers (2007), Revenge of the Fallen (2009), Dark of the Moon (2011), among which this 150-minute fifth installment sequel to the 2014 Age of Extinction shot in 3D Imax is the biggest, the loudest and most stupid with a mythology expanding to 5th century King Arthur.

Mark Wahlberg returns as Texas inventor-mechanic Cade Yeager, the designated "last knight" of the title because he has valour and is, I quote, "pure of heart".

The fate of the world rests on the wizard Merlin's (Stanley Tucci) staff, a magic relic Yeager is summoned to retrieve by British noblemen Sir Edmund Burton in an alliance alongside Oxford University professor Viviane Wembly - Burton is a guardian of the Transformers' history, played by Anthony Hopkins cashing an easy pay cheque; Wembly has English actress Laura Haddock as another of Bay's female sex objects, that is, a Megan Fox with a PhD but the same stripper clothes.

The quest ping-pongs from the prehistoric Stonehenge to Optimus Prime's Cybertron home planet via World War II, three-headed dragons, a John Turturro cameo, Cuba and West Africa.

Back in the United States, meanwhile, in an incomprehensible story credited to four screenwriters including 2002 Academy Award-winner Akiva Goldsman of A Beautiful Mind, the Transformers Reaction Force (TRF) under Josh Duhamel's Colonel William Lennox from the first three movies are wiping out Transformers regardless of faction.

Yeager has become a fugitive for harbouring Autobots in his border town scrapyard; to track him down, the paramilitary squad enlist Megatron (Frank Welker) and his Decepticons.

A primer for the uninitiated: the Decepticons are the hostile enemy robots as opposed to the friendly Autobots, who here add two recruits in Burton's comic-relief butler, Cogman (Jim Carter), and Wembly's French-accented protector Hot Rod (Omar Sy).

The androids both bad and good transform into automobiles to do CG battle, whereupon they become indistinguishable amid the artillery fire, explosions and collisions.

The movie is all artillery fire, explosions and collisions and characters either running from it or shouting over it or taking part in it.

Bay is out of control. He unleashes a full assault of his hyper-aggression for what is reportedly his final franchise entry, pummelling cerebral cortexes into pulp and sucking every soul dry as his parting legacy.

Rating: D-