One night Cat overhears Mr. Sheridan and his colleague Marchmont discussing a valuable diamond hidden in the theatre.

She also meets Johnny, the new prompt with a rather unmistakable talent for art, specifically controversial political cartoons, and a mysterious past of which he does not speak much of, other than the fact he ran away from home at a young age.

Cat soon also finds out that Johnny had had a romantic past with Lady Elizabeth, and would possibly be bidding for her in the marriage market if his situation was different.

Pedro is told of the diamond by Cat, which she later regrets when she finds him looking for it in Mr Sheridan's office hoping it will give him payment for a boat to his homeland in Africa, where he can escape the grasp of slave traders.

Johnny's father Lord Fitzroy, however, knows the true reason to why Cat had the money in the first place, and arranges for her to be set free.