[There's a brief flash of amusement in her eyes.] Oh? Then that answers my second question. Knox's Decalogue is a list of ten rules for mystery writers.

[Beatrice takes a seat, keeping her back straightened. Her tone is authoritative- she knows them well enough.] Knox's first- It's forbidden for the culprit to be anyone not mentioned earlier in the story. Knox's second- It's forbidden for supernatural agencies to be employed as a detective technique.

And so on. Shall I continue?