‘We already have a strong clue,’ said Holmes. `I think that the writer was on board a ship.’ Holmes held up a finger in the air. `Now think about this. Seven weeks after the letter from Pondicherry arrived, his uncle was killed. After the letter from Dundee, it was only three or four days and then his father was killed. What does that tell you?’
‘A greater distance to travel,’ I said.
‘Yes,’ said Holmes. ‘I think the seven weeks after the letter arrived tells us this: the men sent the letter by mail boat but followed in a sailing ship, which is slower. From Dundee, a shorter time was taken. Now this letter has been sent from London, which means there is no time. The men always strike after the time it takes to travel each distance.’
`Goodness me, what does it mean? This relentless pursuit of this family?’ I asked.
`The papers that Openshaw has are of great importance to the person or persons on the sailing ship. I think there are two or more persons involved. One man could not have carried out two murders and fooled everyone. There must be determined men involved. And I think the initials K.K.K are no longer the initials of a man, but of a society.’
`But what society?’ I asked.
`Have you ever heard of the Ku Klux Klan?’ Holmes asked me.
`Indeed, I have not,’ I replied.