"The coroner investigated the case with great care, for doctor Roylott's conduct had long been notorious in the area. He was unable to find any satisfactory cause of death.

My evidence showed that the door had been locked on the inside, and the windows were blocked by old-fashioned shutters with wrought iron bars, which were locked in the night. The walls were checked carefully and were shown to be quite solid all round, and the floor was also thoroughly examined, with the same result.

The chimney is wide, but is blocked by four large bars. It is certain therefore, that my sister was completely alone when she met her end. Besides, there were no marks of any violence on her.

"How about poison?" asked Holmes

"The doctors examined her, but they could not find any".