JOHN Stevenson’s computer-animated sequel to the 2011 family comedy Gnomeo and Juliet opens promisingly with three pointy-hatted garden gnomes congregating around a beautifully bound storybook, deliberating which yarn to spin.

Perhaps Games Of Gnomes? Or how about The Gnome Ranger, Indiana Gnomes or Spider-Man: Gnomecoming? Alas, they settle on a lacklustre misappropriation of Sir Arthur Conan Doyle’s private detective and we spend the next 80 minutes rueing the ornamental trio for denying us the thrills and chuckles of the other contenders.

Written by Ben Zazove, Sherlock Gnomes is a predictable tale of strained friendships, diabolical deeds and gung-ho rescues. Vocal performances fall flat, including Johnny Depp’s plummy take on the titular sleuth, and the script clumsily incorporates characters and phrases from the pages of Conan Doyle’s books.

Star-crossed lovers Gnomeo (voiced by James McAvoy) and Juliet (Emily Blunt) relocate to London with the rest of the ornaments including Lord Redbrick (Michael Caine), Lady Blueberry (Maggie Smith), Benny (Matt Lucas), Nanette (Ashley Jensen), Paris (Stephen Merchant) and Fawn (Ozzy Osbourne).

While Gnomeo and Juliet are otherwise engaged in a flower shop, a shadowy figure kidnaps the newly arrived denizens of the garden. Sherlock Gnomes, sworn protector of London’s garden gnomes, investigates with long-suffering sidekick Watson (Chiwetel Ejiofor).

A scattershot hunt for clues leads Gnomeo, Juliet, Holmes and Watson around the capital via a doll museum, where Sherlock’s ex-girlfriend Irene (Mary J. Blige) presides over a harem of misfit mannequins who seem to have been salvaged from the rejects bin of the Toy Story films.

Sherlock Gnomes is elementary in the most unflattering sense, punctuating the title character’s laboured investigation with perfunctory action sequences set to classics from the Elton John back catalogue (he is one of the film’s executive producers).

McAvoy and Blunt fail to enliven their feuding sweethearts while Demetriou’s Machiavellian mascot is starved of tasty one-liners hard-baked with madness and mischief.

In stark contrast to the writing, animation is polished and seduces the senses. There is no greater disappointment than a beautifully wrapped present with little of appreciable value inside.

RATING: 4/10

DAMON SMITH