Watson had found himself in a mystery, and wrote a letter to describe the problem to his friend Holmes. A friend of Mrs Watson, a proponent of woman’s rights, is seen and the ladies catch up on old times. Her uncle, Colonel Warburton has claimed to be hearing things that aren’t there. Is this a medical case, right up Watson’s alley?
As the old officer, and old doctor compare war stories, an inaudible whistle causes the colonel to think it’s voodoo, and someone is out to get him. Holmes sends a curious telegram. Does the colonel have a dog? Watson doesn’t know why that’s important, but telegrams back there was a dog, but it was recently killed.
Holmes arrives, but is he too late? Is the colonel mad? He may know the secret to prove the colonel is more sane than those around him. What kind of experiment does the detective want to conduct to prove his point? How will it expose the mystery, and who would want to harm the colonel?