"Remember, I've got no idea what this is all about," said the girl when they were in the living room, a narrow room, where blue fought with red witho… - Dashiell Hammett

She keeps trying and you've got to be careful or you'll find yourself believing her, not because she seems to be telling the truth, but simply because you're tired of disbelieving her.

Emotions are useless during business hours.

I didn't know then, and I don't know now, whether she was the owner of the world's best poker face or was just naturally stupid, but whichever she was, she was thoroughly and completely it.