Will Ferrell and John C Reilly play the classic Sir Arthur Conan Doyle characters in Etan Cohen’s spoof, Holmes & Watson. Picture: Netflix

You can feel the flop sweat emanating from the third on-screen pairing of Will Ferrell and John C Reilly.

Making their previous vehicles Step Brothers and Talladega Nights seem the height of comic sophistication by comparison, Holmes & Watson features the duo parodying Arthur Conan Doyle’s famous characters to devastatingly unfunny effect. 

Numerous talented British thespians are wasted in supporting roles in this Christmas turkey that, not surprisingly, wasn’t screened in advance for critics. Although making them troop out to cinemas on Christmas morning is something of which even Ebenezer Scrooge wouldn’t have approved.

Written and directed by Etan Cohen (previously responsible for the similarly witless Ferrell comedy Get Hard), the film begins with a prologue featuring a schoolboy Holmes being bullied by his boarding school classmates. 

The humiliation drives young Sherlock to suppress his emotions in favour of cold, calculating logic, which, as origin stories go, won’t cause Spider-Man to lose any sleep.

Cut to the grown Holmes and Watson attempting to thwart their nemesis, Professor Moriarty (Ralph Fiennes, mainly letting his beard do the acting) and solving crimes. 

When a dead body is found inside a giant birthday cake at Buckingham Palace, the duo is charged by Queen Victoria (Pam Ferris) with the task of investigating the case. 

Assisting them in their efforts are the American Dr Grace Hart (Rebecca Hall) and her mute assistant Millicent (a very funny Lauren Lapkus, who practically steals the film). The two women become love interests for the bachelor duo.

There’s at least one scene that proves mildly amusing, when Holmes silently communicates with his brother Mycroft (Hugh Laurie) via their shared ability to “brainspeak”. It’s a slyly witty moment that contrasts with the otherwise lame slapstick permeating the frenetic proceedings. 

And there’s a strange amount of anachronistic Donald Trump-related humour that falls utterly flat in this context.

Even worse is the laborious scene in which Holmes and Watson desperately try to hide the body of the apparently dead queen, or the Disney-style musical number performed by Ferrell and Reilly that at least sounds authentic thanks to having been composed by Alan Menken and Glenn Slater.

A subplot involving the Titanic seems mainly designed to showcase a cameo by one of the stars of James Cameron’s film about the doomed ship.

Ferrell and Reilly flounder in their titular roles. Kelly Macdonald gamely attempts to score laughs as an atypically young and saucy landlady Mrs Hudson, while Rob Brydon barely makes an impression as the harried Inspector Lestrade.

Despite being filmed entirely in England and at numerous historical locations, Holmes & Watson boasts such ersatz-looking visuals it may as well have been shot on soundstages.

A feeble send-up that doesn’t even manage to be as funny as the Benedict Cumberbatch and Robert Downey jr versions.

IOL