The play starts with a murder in a London street. The victim is Percy Baskerville.
The criminal is Jack the Slipper

Sherlock Holmes is the most famous detective in England.
He likes playing his violin and smoking his pipe

Lucy Baskerville comes to see Sherlock; there is his friend too: doctor Watson

Frederick Baskerville (Lucy's brother) is murdered. Lucy is in danger

Sherlock and doctor Watson go to Baskerville Hall

They meet the mad Mr Sims, the cook, the gardener and the butler

Sherlock disguises himself as Lucy and spends the night

The criminal is the cook

The case of Jack the Slipper is solved: Sherlock and Watson go to Buckingham Palace to meet Queen Victoria