Mary Morstan has received a pearl in the post every year since her father's disappearance. This leads Holmes and Watson to the truth about a secret pact between four convicts during the Indian Rebellion of 1857.
1950
1967
2025
1917
2021
2001
2003
1961
1944
2004
2006
1989
2019
2008
2009
2023
1982
