As early as 1946, French film critic Nino Frank was able to identify a new trend in the American film industry, one that he labeled film noir. Loosely translated, the term described movies that had an overall black or dark nature that described both their cinematographical qualities using light and shadow to create mood and their subject matter that often dealt in criminal activity or an emotionally oppressive atmosphere. This last was often depicted in literal terms as the descent of characters from naive or law-abiding citizens into desperate, hunted souls. Here are the cold-blooded killers, crusading cops, stolid Feds, stoolies, ex-cons, femme fatales, long suffering wives and lovers, conniving grifters, and innocent dupes that populate an underworld that most people never encounter in their daily lives. In Gats, Gams, and Guts: A Field Guide to the Dark World of Film Noir the best examples of the genre are presented in handy to read and accessible capsule reviews highlighting the actors and actresses, the directors and scriptwriters, and the cinematographers and novelists who inadvertently created a uniquely American cinematic form.