But what has left an even sharper impression on my memory was the blackness that then began crawling over his face, obliterating the features, concealing their human outline, and hiding him inch by inch from view. This was my first realisation that the process of materialisation was at work. His visage became shrouded. I moved from one side to the other to keep him in view, and it was only then I understood that, properly speaking, the blackness was not upon the countenance of Colonel Wragge, but that something had inserted itself between me and him, thus screening his face with the effect of a dark veil. Something that apparently rose through the floor was passing slowly into the air above the table and above the bowl. The blood in the bowl, moreover, was considerably less than before.