Robert Downey Jr’s manic, mischievous, unexpectedly kick-ass hero returns for a sequel that is even more knockabout and irreverent than its predecessor.

However, the offbeat touches that seemed charmingly quirky first time around are now in danger of turning irritating.  Downey Jr’s Holmes spends so much time prancing around in a variety of disguises in the film’s first half that it’s a wonder the plot ever gets going.

When the story gets going, it turns into a rip-roaring adventure  revolving around Holmes’ efforts to thwart his criminal nemesis, Professor Moriarty (Jared Harris), who is scheming to propel Europe into war through a wave of bombings and assassinations across the continent.

Along the way, director Guy Ritchie stages the action with rumbustious vigour, giving Downey Jr’s Bond-like Holmes the chance to deploy as much brawn as brain. Jude Law has plenty of moments to shine, too, as Holmes’ put-upon Watson and Harris supplies quietly sinister, understated villainy.

Playing a gypsy fortune-teller who may or may not hold a vital clue to solving the case, Noomi Rapace makes a strong impression, as does an excellent Stephen Fry as Holmes’ smarter brother, Mycroft, who spends almost half his screen time naked (naughty bits artfully masked).

This is over-indulgent, then, but it’s fast-paced, rollicking good fun – and there’s a standout sequence when our heroes come under attack in a forest.