Holmes & Watson receive a letter from an informant who known by the pseudonym Fred Porlock. Porlock is a man well connected with criminals. The letter is written in code, and Holmes determines that the code comes from the words in a book. They decipher the code by page and column and find that John Douglas of Birlstone House is in danger.
Unfortunately the movie Sherlock Holmes and the Valley of Fear is not yet available on HBO Max.
| Production | Joy Craste | Production Coordinator |
| Writing | Arthur Conan Doyle | Novel |
| Editing | Peter Jennings | Editor |
| Editing | Caroline Neave | Editor |
| Production | Roz Phillips | Production Manager |
| Visual Effects | Kim Craste | Animation Supervisor |
| Directing | Norma Green | Director |
| Writing | Norma Green | Adaptation |
