Near Epping Forest, strange light phenomena are occurring. An eyewitness reports seeing the Northern Lights. Moriarty becomes aware of a brief newspaper article and travels with Crowley and Theodora Sachs to the ruins of Markham Manor, where the lights were observed. He connects the phenomenon to an invention that was stolen from Professor Payne's London laboratory - a device that generates a green beam of fire using electricity and could become a devastating weapon. At Markham Manor, Moriarty narrowly escapes a sinister assassination attempt. A dangerous hunt for the green fire ensues.