Oscar winner Bill Condon reunites with Ian McKellen to take on the world's greatest detective in a case that's very close to home.
Based on Mitch Cullen's 2005 novel A Slight Trick of the Mind, Jeffrey Hatcher's screenplay sees Sherlock Holmes (Ian McKellen) as a frail and fragile 93-year-old retiree, who tends to his beloved bees by the seaside in Kent, with his brusque housekeeper Mrs Munro (Laura Linney) and her 14-year-old son, Roger (Milo Parker).
His memory is giving out and his once razor-sharp mind is struggling to uncover the details of a bereaved couple and his own retirement 30 years ago.
As Holmes desperately tries to piece together what went wrong with his final case, beautifully executed flashback scenes transport us to 1919. A quirky scene involving Frances de la Tour as an eccentric glass harmonica music teacher makes for a rewarding subplot.
Fast forward 20 years and we see Holmes leaving Baker Street for Japan on the hunt for the prickly ash plant, which he believes will slow the deterioration of his brain cells - a heartfelt scene which will resonate deeply with anyone who has watched a loved one affected by the ravages of age.
Condon does a superb job of humanising Holmes and exploring the vulnerability of someone living with illness. Equally, writer Hatcher is at the top of his game, switching between timelines and sub-plots seamlessly.
McKellen, minus his deerstalker hat and pipe, adds new depth to the iconic super-sleuth, playing a man who is confronted with his own mortality with conviction.
Milo Parker is prefect as young Roger and a star in the making (watch this space!), while Laura Linney is outstanding as ever, although her Welsh accent is wobbly at times.
Mr Holmes won't keep you guessing throughout but the movie reminds us that regret is one of life's most dangerous pollutants.
Who would you like to be by your side in your final days? Perhaps, that is one of life's biggest mysteries that will never be solved.
Laura Delaney