Filmmaker Guy Ritchie saw him as an unkempt martial arts expert with an American accent. The creators of the television series Elementary regarded him as a recovering drug addict. The British television show refracted him through Benedict Cumberbatch.

It was a matter of time before the continuing cycle of revisions and updates on Sherlock Holmes placed the detective on the edge of life and death and memory and forgetfulness. Mr Holmes, Bill Condon’s partially engaging adaptation of Mitch Cullins’s novel A Slight Trick of the Mind, imagines Arthur Conan Doyle’s enduring creation as a 93-year-old pensioner. It’s 1947, and Holmes has retired to his country cottage to tend to bees and befriend Roger (Milo Parker), the son of the housekeeper (Laura Linney). Holmes too is in revisionist mode: he is rewriting partner John Watson’s account of his last case. Sherlock Holmes wants to present another side of Sherlock Holmes, but he cannot remember enough to do so.

Holmes’s shaky present is punctuated by medical hiccups, his obsession with regenerative herbs (a clever replacement for his supposed cocaine habit) and his growing closeness to George, whose curiosity provides the excuse for two sets of flashbacks. One relates to Holmes’s last outing, in which he follows a young woman who has taken a strange liking to harmonica lessons. The other has to do with a trip to Japan, whose main function seems to be to introduce a touch of Zen to the picturesque English countryside.

Remembering Holmes

The movie neatly simplifies complex questions about who owns Holmes’s legacy – the embellishment-favouring Watson, the man himself, or his admirers – but cannot always handle the developing triangle between Holmes, Roger and Linney’s housekeeper, she of poor characterisation and dodgy accent. The dialogue is sharp but the pacing often isn’t, especially when it is time to tie together two flashbacks and the question of George’s fate.

The proceedings are held together by McKellen’s compelling performance and his deft switches between a spry 70-something and a precarious 93-year-old who looks back on his fame with amusement and regret. In one sequence, Holmes watches a film adaptation of the story that he is attempting to rewrite and concludes that the dramatisation is overdone.

Condon ensures that his film is bereft of melodrama or, for that matter, mystery. Mr Holmes is more a study of ageing than a satisfactory deconstruction of Sherlock Holmes’s literary legacy. It is respectful of its lead character’s advanced years and the period setting. The unhurried and sometimes plodding drama gives its lead character the necessary expanse to consider the meaning of his life. His conclusions are banal, but McKellen brings wisdom and wit to the metaphysical investigation.