I can think of no better way of beginning this brooding tale, than by quoting Doctor Hesselius briefly on the subject of haunted men, and then introducing him to tell it, to quote "In a rough way, we can reduce all such cases to three distinct classes. Some of those who by conscience are subject to illusions. Others are truly infested by spiritual agencies beyond their control, and the third are affected by some systemic disease which clouds their functions and destroys objective thought. Had I seen James Barton soon enough, I might have read his problem."