“Not of a single man, acting upon any rational motive,” replied Mr. Ludgrove. “Even in the brain of a homicidal maniac there is usually traceable some dim guiding principle. He either conceives a hatred for a certain class of person, or he kills indiscriminately, usually selecting the people nearest to hand. In this case the selection was anything, but indiscriminate. Mind, I am assuming for the moment, as apparently you are yourself, that the death of all six was the direct sequel of their receipt of a numbered counter. If you adopt the theory that a single man is responsible, you may as well believe in the existence of the black sailor.”

“I am afraid that we are already committed to him,” said Hanslet with a smile. “You see, we offered a reward for him, and it would never do for the police to admit that they had offered a reward for a ghost. Whyland, what is your honest opinion of this black sailor?”