A modern update finds the famous sleuth and his doctor partner solving crime in 21st century London.
Sherlock waits to see where Moriarty will make his posthumous move. One mysterious case in particular baffles Scotland Yard - but Sherlock is more interested in a seemingly-trivial detail. Why is someone destroying images of the late Prime Minister Margaret Thatcher? Is there a madman on the loose? Or is there a much darker purpose at work? Something with its roots deep in Mary Watson's past…
Sherlock faces perhaps the most chilling enemy of his long career: the powerful and seemingly unassailable Culverton Smith - a man with a very dark secret indeed.
Holmes and Watson travel to Europe to escape Moriarty's vengeance.