Understanding the ending *SPOILERS*
First impression: My first impression of the film's ending was that Watson had finally admitted to loving Holmes, and that she wouldn't live without him. The sound they heard was not a horse, but instead an oncoming train. Watson could see only the horse at this point, just like Holmes. The light shining on their face, made me believe that it was definately a train, and both Holmes and Watson were struck and killed just as the film ends.
Second opinion: My second opinion of the film's ending was that Watson had finally admitted to loving Holmes, and that she wouldn't live without him. The sound they heard, which they assumed a horse, was completely imaginary. There Holmes stood at a dark tunnel, and Watson, for the first time was a part of Holmes' insanity. Together they both stood there staring at nothing with a mutual belief that a horse was approaching. The light shining on their face only gave the viewer(s) visualization of what both Holmes and Watson merely imagined.
On any note, "They Might Be Giants" (1971) was one of the more tragically beautiful stories in film history.
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