Dr. Mortimer seems to believe that there is an element of the supernatural at work. He reports that “…several people had seen a creature upon the moor which corresponds with this Baskerville demon, and which could not possibly be any animal known to science. They all agreed that it was a huge creature, luminous, ghastly, and spectral.” What is Holmes’s reaction to this story? Does he believe that the problem is supernatural, or can it be explained scientifically?