I have just bought 'Gashlycrumb Tinies' by Edward Gorey an American artist, His characteristic pen-and-ink drawings often depict vaguely unsettling narrative scenes in Victorian and Edwardian settings. At first they seem innocent and playful but when you study the images a little longer, they are very dark and sinister. The themes in his work is really relevant for the current project I am working on 'Moral Consequences'. I also have a dark theme within my own work, another interesting element within his work is the connection between childhood innocence and fear.
Edward Gorey's website - http://www.edwardgoreyhouse.org/