Leon Garfield 
Ghost Downstairs 

A bargain of a lifetime – seven years off the end of his life in exchange for a fortune now!By day, Mr Fast was a solicitor s clerk, drawing up strangle-tight agreements and contracts. By night he repaired to his rooms to spy upon his neighbours (for he had no friends) and to dream of being richer than other men. But when old Mr FIshbane offers him what he most desires in return for seven years off the end of his life, he could never imagine the little lost spectre that will come to haunt him . . .Another remarkable novel from Leon Garfield.