Joseph was a mad scientist from Leicester who designed a deadly poison made from the amonita mushroom, the angel of death or devil's cap which he gave to Vaisey of Nottingham to use as a chemical weapon, poisoning the townsfolk of Pitts Street by impersonating the the night watchman. A delusional sociopath, he was obsessed with becoming known in history for his invention and ridding the world of "vermin", the poor. After being poisoned himself by Will Scarlett in an assassination attempt on the Sheriff, Joseph was angered when Robin Hood revealed Little John had found a cure in the woodman's remedy, belladonna. In a rage, he attempted to stab Robin, but the ensuing scuffle saw them both fall out the window of the castle, with Joseph falling to his death despite Robin's attempt to help him.