Miss Sharples

In the novel Curtain, Miss Sharples (christian names unknown) was the invalid aunt of Freda Clay, who looked after her. Freda deliberately gave her an overdose of morphia and killed her. She claimed she had mistaken the quantity of sedative she was meant to give to her aunt; the police believed Freda had killed Miss Sharples but they didn't have enough evidence to prosecute.

Both Miss Sharples and Freda Clay do not appear in the novel.

Role in the novel
It is revealed that Miss Sharples was the third victim of Stephen Norton, who mentally manipulated people into killing their relatives without knowing what was happening.