Ashes to Ashes was my attempt at a serious police procedural. I did a lot of research. An arson investigator told me that you can smell accelerant (gasoline, kerosene, whatever) even if a fire destroys the whole building. I visited a warehouse that had burned down to a couple of standing steel pillars and a cracked cement floor. Flammables had been stored in the building, and even though the fire had taken place weeks ago, sure enough, you could still smell fuel oil. A friend asked me to use his name for a character in my next book, so I did. And during the research, this character came to look a lot like a fireman who was extremely helpful about the details of fighting fires. Before the end, the character died of a heart attack -- and both my friends now have heart problems. I never again will name a doomed character after anyone I know.