故事发生二战时期,《福尔摩斯在华盛》展现的是福尔摩斯和华生智斗纳粹间谍的故事。一位负责将绝密胶片从英格兰送往华盛顿的英国间谍在任务途中神秘地失踪了。由于担心自身的安全,他将胶卷藏在火车上一位不知情的女士那里后,自己也躲了起来。当局被告知此事后,福尔摩斯奉命调查。英国政府要求福尔摩斯和华生前往华盛顿,赶在胶片落入敌手之前查出真相,否则,英国及同盟国将损失惨重。面对国际间谍,福尔摩斯争分夺秒,寻找线索,在造成重大损失前擒获间谍找回了胶片。Sherlock Holmes is engaged by the Home Office to locate a British subject traveling for his law firm to Washington, D.C. The man had flown to New York City and then took the train to Washington. On the outskirts of the city, the man was kidnapped and has not been seen for several days now. Holmes learns from the Home Office that the man was in fact a government agent who was delivering a highly secret, two page document to the US government. In verifying the contents at his flat, Holmes concludes the document had been reduced to microfilm. The question becomes whether he may have had the opportunity to pass the microfilm to someone else on the train before he was taken.