I want my books to be grounded in history and to make my readers to feel what it was like in those times. To do that, I try to place myself in the 1910s mentally and visually. Details matter, and I try hard to get them right: the sights and smells of the times, the contemporary terminology, the weapons, the means of transportation, the fashions, the politics, and the places themselves. Old postcards and pictures are invaluable tools visually. I have a bookcase full of WWI books and 6 files of research material. For example, I found a street-by-street map of 1921 Berlin. Gold. In a So Beware chase scene, I can go block-by-block and street name by street name.