In the field of supernatural and fantastic literature, certain names come readily to mind - E.T.A. Hoffmann, Edgar Allan Poe, H.P. Lovecraft - but the name of Fitz-James O'Brien has been unjustly overlooked and nearly forgotten since his premature death in 1862 during the American Civil War. 'The Diamond Lens', O'Brien's most famous short story, can be regarded as a forerunner of the science-fiction genre; 'What Was It?' is alleged to have served as a model for H.G. Wells's 'The Invisible Man'; and 'The Wondersmith' is a marvellous tale of Hoffmannesque invention. Taken together, O'Brien's few surviving stories give him an important place in the development of American fiction and remain as fresh today as when they first written almost a hundred and fifty years ago.