Adopted sisters Lana Beth and Emma Jane are polar opposites, but when the same strange 'tattoo' suddenly appears and winds its way up their bodies within days of each other, they soon realise there's more to their relationship than they could ever have imagined. Sent off to London for two weeks of 'work experience', the Morgan Sisters soon find themselves being initiated into the ancient Praxos Foundation, one that protects the innocent while fighting evil, both human and supernatural. At the same time, Lana Beth and Emma Jane must also investigate why the sweet but sometimes pesky ghost of Josiah Grimshaw just won't leave them alone.