The Magician's Nephew

S11 E5: Jean Wildacre, a grandmother and magician's assistant, drops dead during a stage show, poisoned by a deadly tropical frog. Barnaby and Jones investigate the secretive world of Midsomer's Magic Circle - a group of friends who once formed a cult together. Ernest Balliol and his family are still obsessed with black magic, and fellow villager Aloysius Wilmington has caused upset by exposing their rituals as fakes.