Mary Montresor

In the short story The Golden Ball, Mary Montresor is a wealthy society girl. She is described as beautiful and highly popular, with her picture appearing in the illustrated newspapers at least four times a month. She is also extremely well-off, with an income of some twenty thousand pounds a year. Although she is engaged to the Duke of Edgehill, she does not treat the event as final and is continually in search of the ideal person to be her husband. It is under these circumstances that she met George Dundas while driving her sports car around the streets of London.

Mary has designed a test to determine if a given person would qualify as a suitable prospective husband. According to Mary, at the time she met George, "nine and a half" people had failed the test. The "half" was the Duke but Mary does not explain why he is only considered "half"--whether he only took half the test, only failed half of it, or even if she considered him only half a man.