Who Killed Charmian Karslake‪?‬

"Beastly mess the place seems to be in," grumbled Sir Arthur Penn-Moreton, looking round the room with a disgusted air.
"Well, if you will give balls you have to put up with the aftermath," said Dicky, his younger brother, screwing his monocle in his left eye as he spoke.
Dicky was already seated at the table devouring kidneys and bacon with apparent relish.
Sir Arthur glanced at him as he sat down opposite. "You don't look up to much this morning, Dicky!"
"How can a chap look up to much when he has sat up to the small hours of the night before, dancing round with a lot of screaming young women, and eating all sorts of indigestible food?" Dicky questioned, taking another helping of kidney. "You don't look any great shakes yourself for that matter. We are neither of us in our first youth, Arthur, you must remember. Years will tell, you know."