Agatha at her most tongue-in-cheek:
Edna restored the toffee to the centre of her tongue and, sucking pleasurably, resumed her typing of Naked Love by Armand Levine. Its painstaking eroticism left her uninterested—as indeed it did most of Mr. Levine’s readers, in spite of his efforts. He was a notable example of the fact that nothing can be duller than dull pornography.
And, I loved this:
“Also, I may be going to see a specialist,” said Colin.
“A specialist? What for? What’s wrong with you?”
“Nothing—bar thickheadedness. I don’t mean that kind of a specialist. One in your line.”
“No. A private detective—a friend of my Dad’s—and a friend of mine.This fantastic business of yours will be just down his street. He’ll love it—it will cheer him up. I’ve an idea he needs cheering up.”
“What’s his name?”
“I’ve heard of him. I thought he was dead.”
“He’s not dead. But I have a feeling he’s bored. That’s worse.”