Dr. John Watson treats a patient who has lost a thumb. The patient says that the loss of his thumb was not an accident but the result of an attack. However, he fears that the story behind the loss of his digit is so strange that the police will not believe it.
Unfortunately the movie The Engineer's Thumb is not yet available on HBO Max.
| Directing | George Ridgwell | Director |
| Writing | P.L. Mannock | Writer |
| Writing | Arthur Conan Doyle | Story |
| Writing | Geoffrey Malins | Writer |
