Mr.Richards was invisible.

His meals went up daily.
Ogden and Kate visited him daily, but the baize door was always locked, and Ogden and Kate, on the subject, were dumb.

Kate visited the invalid at all hours, by night and by day.

Ogden rarely left him except when Miss Danton was there, and then he took a little airing in the garden.
Rose's room was near the corridor leading to the green baize room; and often awaking "in the dead waste and middle of the night," she would steal to that mysterious room to listen.

But nothing was ever to be heard, nothing ever to be seen--the mystery was fathomless.