Considerable Advantage

An author searching for his family roots discovers a journal written by his great-grandfather. The journal contains remarkable revelations and curious items of physical evidence relating to murder and political conspiracy at the height of Victorian England's golden age of progress. Concerned that the decaying journal will not survive another hundred and forty years in storage, the author transcribes the work into print for future generations, but is dying thanks entirely to the diary's peculiar contents.
In 1862, the journal's author, an aspiring writer, receives a strange and profitable commission from the son of a deceased and disgraced politician. Clearly, the commission is to the author's considerable advantage, and he agrees to accurately chronicle the events described to him by Sir Edward Carston. However, it soon becomes clear that in accepting the offer, George T Kelly has unwittingly placed his own life in dire jeopardy...