In "The Final Problem", Sherlock Holmes finds himself locked in a dangerous battle of wits against Professor Moriarty, the mastermind behind London's criminal underworld. Aware of the growing threat, Holmes and Watson flee to Switzerland in an attempt to evade Moriarty's reach. As the pursuit intensifies, Holmes devises a plan to end Moriarty's influence once and for all, leading to a fateful confrontation at the Reichenbach Falls.