su-lin should write something like the diana wynne jones tough guide, only for detective novels, something called maxims for living, such as, don't be in a hurry to suspect someone, because he is always the second to be murdered, and when people ring you up and ask you to meet them you should always ring back to check, or else have a codephrase, and always beware of a man with a gammy leg. su-lin would do an admirable job.