Thirteen years ago a Paladin, Tanril and a Witch, Cassandra met by chance, Cassandra searching for her cousin who had run away after her parents had died, and Tanril investigating a rash of disappearing orphans in the area. Through their research they discovered that similar things had been happening for hundreds of years, all over Ustalav. They eventually catch wind of a vampire of the rare Vetala breed, called the Daughter of Nightmares, who acts as a recruiter for the shadowy Whispering Way. The foul creature disguises herself as a young girl, no more than the age of six, and befriends the children of the streets before taking them 'somewhere safe' to be inducted into the dark organization themselves.
Reluctantly using a gnomish ally as bait, the two snuck into the vampires hideout to destroy her coffin and rescue the Cassandra's cousin, but what they found with it shook them to their souls. The vampire wasn't just pretending to be a six year old girl, she was one. Her parents had been followers of the Whispering Way themselves and, when she had been caught in the crossfire between their sect and a group of Paladins, they had her turned and offered her to their dark masters for the rest of her incredibly long existence. She had been forced to locate children to induct into the evil cult for eight hundred years, commanded by powerful magic compulsions and the need of a child to obey their parents wishes.
Tears in their eyes, the two women turned to leave, only to be stopped by two figures blocking the doorway. The Daughter of Nightmares looked at them, their gnomish friend held dead in one hand, and pleaded for their forgiveness before brutally attacking. They defeated her, with difficulty, and with her last breath the girl thanked them for putting her to rest, and ending the darkness that she had become.
But an ancient Vetala does not die so easily. The stored consciousness of centuries of grief instinctively lashed out, and would have killed them in their victory, but Eliza, Cassandra's cousin who was six herself, took it into herself and clensed it. Eliza and the consciousness that calls itself Margret now share a body, neither knowing the truth of what they really are, as the dark memories were locked away by the power of their merging.
Cassandra had always intended to adopt Eliza, but now that she would be raising the equivalent of two little girls she asked for the assistance of the woman she had grown to admire, and who had helped her so much in the past six months of their adventure. The family has lived in a small town a day and a half's ride from Lepidstadt in the witch's childhood home. They called on Professor Lorrimor, a contact who had explained the species of vampire to them, early on to help with understanding Eliza's bond with Margret, but they eventually accepted the phantom girl with as much love as the daughter she is bonded to. The girls view eachother as sisters, and share the body mostly evenly when joined, discussing important decisions whenever they have the chance.
Neither really remember anything until their adoption, but their mothers tell them that Eliza's birth parents were killed when they got too close to uncovering the truth about something very dark, and to cherish what memories they did have. Despite this, they are mostly happy young women, if a bit mischievous to the chagrin of Tanril. They remembers Mr. Lorrimor, vaguely, from the first few years of their new life, and remembered he had called them 'fascinating', which they had taken as a compliment, although they didn't know what it meant at the time, and still doesn't know why he said it. Five days ago a message came, informing them of the old man's death and requesting the girls presence at his funeral. Their mothers where reluctant to let them go when a message came, but they eventually relented. As their carriage approaches Rivengro, she is unaware that this trip would be the one that changes their entire life, by revealing its past secrets.
