This is another story about a document that has great political implications. It has disappeared and Holmes has been brought in as a last resort. The keeper of the document (as is nearly always the case) has been careless and overconfident in his own abilities to maintain secrecy, and falls victim to those who would feast on his carelessness. The second kicker is the young woman, who has fallen victim to blackmail because of exposing herself through correspondence. We are not let in on the specific details of her plight, but we know that she is implicated in some pretty serious business. A well known spy/thief has been murdered and during the investigation a blood stain is found on a carpet. Oddly, the blood has not seeped through to the floor, at least in the current position of the rug. However, there is a second stain at another corner. This leads Holmes to realize that a police detective has screwed things up, allowing the strong box which contained the important document to be compromised. The lady is involved but probably didn't know the gravity of the situation. The task is simple: Recover the document and save the lady's honor. Some are unsatisfied with the conclusion. I tend to applaud it as quite satisfying. We must remember that Holmes often plays by his own rules. What I really liked about this series is that as quirky as Jeremy Brett's portrayal was, he had a soft spot for some of the victims and felt he could set aside his indifference at times.