Sherlock Holmes and his faithful friend, Dr John Watson, have been hired by actor George Reynolds to help him solve a puzzle. George wants them to find out why the audience who comes to see him perform every night are the same people, only wearing disguises. Is something sinister going on and, if so, what?

Meanwhile, Holmes’ archenemy, Professor James Moriarty is having problems of his own. Implicated in the murder of a gang leader, Moriarty and his second, Moran, must go on the run from the police in order to find out who is behind the set-up.

But their investigation puts them in the way of Holmes and Watson and it’s not long before all four realise that they are being targeted by the same person. With lives on the line, not just their own, they must form an uneasy alliance in order to unmask the true villain. With clues leading them to a hotel in Switzerland and a conspiracy far greater than any of them expected, who can be trusted – and will anyone of them survive?