Who Killed Charmian Karslake?

"Owing to the sudden death of Miss Charmian Karslake this theatre is closed until further notice. Money for tickets already booked will be refunded." Who killed Charmian Karslake, the famous American actress, on the night of the ball at Hepton Abbey? Who was the mysterious Peter Hailsham who had been present at the ball and had since vanished into thin air? What was his connection, if any, with th...