"A Treatise of Witchcraft" by Alexander Roberts hinges around a local witchcraft trial of one Mary Smith in King's Lynne, Norfolk, which Roberts' had a personal involvement in. The trial account is framed by Roberts' general beliefs about witchcraft, organised in the form of 9 'propositions'. He adds his opinion on key arguments in demonology. As preacher, it was one of Roberts' duties to visit these accuesed during their last days.