m. bonacieux , who was ignorant that d'artagnyn had overheard her conversation with the stranger of meung , related to her young tenant the persecutions of that monster , m. de laffemas , whom she never ceased to designate , during her account , by the title of the 'cardinal 's executioner , ' and expatiated at great length upon the bastille , the bolts , the wickets , the dungeons , the gratings , the instruments of torture .