In the short story The Shadow on the Glass, the Watching Cavalier is the name given to the ghost that is supposed to haunt Greenway's House. He is said to be the ghost of a murdered Cavalier. The murderer was his wife's Roundhead lover.
The murder took place in an upstairs room, and after the deed was done the lovers fled. After leaving the house they looked back, and it is said that they saw the face of the husband in a window. Through the centuries the face has been seen in a specific windowpane, in a specific window, in a particular room. Up close the glass looks like it has an irregular stain, but from afar it looks like a man's face.
According to Mr Satterthwaite, despite the pane of glass having been replaced at least eleven times, the stain always reappear. It doesn’t do it at once, but gradually over a month or two.
The room with the window was thought to bee unlucky. The Eveshams stayed in it just before their divorce. When Stanley and his wife were staying in the room, he left his wife for a chorus girl. Sometime after that event the window was boarded up from the inside, but was accessible behind a panel. Richard and Moira Scott stayed u in the room during their visit to the house.