When Troy and his mammoth both spear the same lemon with zinc and copper lances during the annual Mammoth Island lemon harvest, they receive an electric shock. Following this, Brenda and Pilbeam attempt to soothe the mammoth by grooming it with plastic combs; this creates static electricity, attracting litter from across the village. Subsequently, the Inventor explains the basic principles of electricity to the islanders who use the acidic qualities of lemons to help them power their machinery to increase the yield of the harvest. Topics covered: electricity, current, positive and negative charge, static electricity, acid, batteries, circuits.
