In Michael controversial work the last Sherlock Holmes story set towards end of 19th century in London what is surprise twist at end?

You're likely thinking of "The Adventure of the Second Stain" by Sir Arthur Conan Doyle, published in 1892. While it's not the *last* Holmes story chronologically, it's known for its dramatic twist ending.

The surprise twist is that the "Second Stain," a dangerous document that the villain is trying to steal, turns out to be a forged document created by the villain himself. He's manipulating the situation to gain political power and discredit his enemies.

This twist makes for a gripping conclusion, as it reveals the villain's cunning and emphasizes the importance of careful investigation and critical thinking that Sherlock Holmes is known for.