Investigative Techniques

Detritus was particularly good when it came to asking questions. He had three basic ones. They were the direct ("Did you do it?"), the persistent ("Are you sure it wasn't you that done it?") and the subtle ("It was you what done it, wasn't it?"). Although they were not the most cunning questions ever devised, Detritus's talent was to go on patiently asking them for hours on end, until he got the right answer, which was generally something like: "Yes! Yes! I did it! I did it! Now please tell me what it was I did!"

-- Feet of Clay, Terry Pratchett